He is a member of the Dark Nebula, being their second most powerful beyblader after Ryuga. For the most part he was assigned to watching over Gingka to study his Pegasus.
Later he takes part in the Battle Bladers Tournament where he follows a strategy of attacking opponents weakly to make them lower their guard and become vulnerable to the ultimate assult of his Poison Serpent SW145SD.
Reiji is a noticeably pale, skinny boy with red hair with a blonde streak running through the front of fringe. His eyes are bright yellow, but they seldom show as his fringe covers them.
He wears a long blue shirt with a snake-scale pattern across the bottom of his shirt along with a scale pattern on the cuffs on the arms. His jeans are black. A notable feature of his appearance are snake eye styled hair clips. He often walks sloppily, wavering and never actually walking straight or standing up straight. When talking, he has a habit of pointing with his fingers.
Reiji is a boy who's personality changes drastically when he enters a battle. Outside of bey-fights he is rarely seen talking and seems content just observing what is happening around him. The same behavior is often displayed even when a battle has started - it is only when a bey battle gets more heated that he begins speaking and showing his true colors.
Reiji's battling style is based on his sadistic personality. He prefers playing with his opponents cruelly to ending the battles as fast as he's able to. If there is one thing Reiji enjoys, it is the fear of others. He can't understand a battling style based on enjoyment and friendship. Rather, Gingka having fun even in facing him is highly unsettling to Reiji. It even appears that the concept of positive bey spirit causes him physical pain in form of headaches.
Beyblade: Metal Fusion
Reiji first appears at the Battle Bladers tournament, when is assigned to battle Hyoma. At his introduction, Blader DJ mentions that there is no information on Reiji as a person or on his beyblade.
His battle against Hyoma first appears rather one-sided, with Hyoma winning. However, when things appear decided, Reiji finally begins attacking fiercly. Reiji could end the battle with ease, but instead he proceeds to slowly torture Hyoma's Aries and break the bey in the process. Only when Hyoma is begging him to stop, Reiji finally ends the prolonged fight and wins.
Reiji next appears, when he fights Yu as punishment for Yu's loss against Gingka at Battle Bladers. Yu is told that he'll be set free if he is able to beat Reiji. In their battle, Reiji follows the same strategy he used against Hyoma, which he calls 'Serpent's Poison'. While he appears to turn out victorious, the battle is not finished. Yu uses his special move and uses the resulting confusion to run away.
Back in Battle Bladers, Reiji has to face Kenta. He starts out by following his usual strategy, but then begins to break off Sagittario's claws one by one. Still, Sagittario is not defeated this easily. Kenta, who has combined his beyblade with Yu's performance tip for this battle, begins speaking of the friendship that makes him this strong. At this point, Reiji gets angry for the first time, unable to stand what Kenta is saying. Finally, his real eyes show between his hair. In this state of rage, Reiji begins damaging Sagittario more and more and finally stops Sagittario's rotation with his Dark Move. While this is his formal victory, Reiji states to not be satisfied with the extent of destruction yet and continues attacking Kenta's bey. In an attempt to protect his beyblade, Kenta enters the arena himself. Reiji might have attacked him as well, had it not been for Gingka's interference.
Gingka is also Reiji's next opponent in the tournament. In this fight, Reiji reveals that the Dark Nebula has watching Gingka's battles in a Dark Nebula room filled with screens. He's always wanted to defeat Gingka and erase that positivity of his. As their fight goes on, it appears as if Reiji is about to defeat Gingka, who's seemingly turned to stone with negative emotion. However, Gingka breaks free and declares that he is still having fun battling Reiji. Reiji can't understand why Gingka is not afraid of him. He starts to lose composure and attacks again. Gingka finally finds an effective strategy - he blocks Reiji's attacks by mirroring his movements. Reiji finally feels fear himself as he notices Gingka, who is still smiling, is about to win. He is defeated and breaks down.
The last time he's seen is on the ending picture of the season, walking away from the celebrating other characters.
Poison Serpent SW145SD: Reiji's primary beyblade in Beyblade: Metal Fusion. It is a powerful balance type with incredible attack and defense capabilities and precautions. It's spin track and fusion wheel optimize for it's greatest endurance and balance. As a snake it has the ability to wear the opponent down with every hit, infecting the victim with poison. One feature Reiji noted about his bey is that the spin track has two sets of fangs. While the blades are reversed they are defense fangs which can withstand an opponents attack, but in its original forward motion they become attack fangs which ware down and destroy an opponents bey.
Venom Strike: Serpent unleashes a flurry of attacks to ultimately poison and defeat the opponent. It is referred to as a "Dark Move".
"You're wrong; it's not so I can defeat you, it's so I can destroy your entire being."
"This can't be the end of this, entertain me more pretty please, at this point there's no fun in breaking you"
"At this point there's no fun in breaking you."
"You've started to fall apart nicely: more, struggle more, more! Become more frightened and don't give up! You should stop trying and become nothing just like that worthless bey."
"What is Beyblade you ask? Do you tell me then, Hyoma. You're scared. You're just so scared that you don't know what to do next, do you? Too bad because you can't run from me anymore, that's a fact. I'll defeat you so completely that you'll never be able to pick up a bey again."
"No it won't, not quite yet"
"Now that was a fun battle"
"That was the best thing for your Bey"
"The losers become food fore the Dragon"
"But before that I need your help. You don't mind helping me with my warm-up, do you little buddy?"
"Don't be like that"
"It looks like the poison has taken effect."
"Could be ; even now , Poison Serpent's poison is working it's way through Libra ; if you do nothing , if you don't try to attack ; you will definitely end-up with a sleep-out"
"I told you already didn't I : Libra has already been affected by Serpent's poison understand"
""Why" you say; don't you understand what those are down there : they're fragments of Libra's parts , that Serpent has broken off"
"Even a tiny fragment is a fatal wound for a bey, this loss causes the bey to lose it's balance and it's power is gradually drained away, it's as if a snake's poison was circulating through it's entire body.
"The reality is; without using my full strength, your power has been completely drained; that's the taste of ssadnesss, seeing your precious bey cut-up right before your eyes can't be fun; this is true sorrow; next for you; this is fear; I'll give you a good taste of my Dark Move that is: Serpent Venom Strike"
"Well shall I pull an end to this now"
"I heard the same thing from that kid Yu , but , as an answer I pounded fear into the little guy's very core ; I'll show the same fate to you soon enough with this Poison Serpent"
"Hun , not bad , but Serpent's poison should be steadily working it's way through your bey as we speak ; let's see if you can keep up with this movement"
"No way , how is he able to follow"
"What's going on ; Serpent's barrage attacks seem to have done it's job well enough ; so why isn't the poison circulating"
"Don't get too exited ; if this is your plan, then I'll inject all my poison at once ; show your fangs Sserpent"
"One claw gone ,two claws, hey there little buddy if you don't hurry and run away that last claw will be gone too ; three claws ; now it's over"
"Interesting ; if you wouldn't have used that silly trick it would have been over with that last hit ; but now your suffering will have to continue"
"Not enough ; I will crush all of it's parts"
"You're not fighting alone you say you, you won't back down, not now not ever, interesting, I wander can you keep saying such things as you watch your bey turn to dust before your eyes"
"That's good ; don't give up just yet ; that way I'll get more pleasure from breaking you"
"Well, how does it feel to not be able to do anything as your precious bey is destroyed^Feeling a bit cold ; like maybe your fear was turning to stone ; tell me how it feels to have your bey's fusion wheel, spin track and performance tip broken apart when you can't do anything ; look at your broken bey ; what can you do with a bey like that ; you can't complete you goal and you can't fulfill your promise to your friends ; right now ; you are the same as that useless bey"
"He acts like nothing happened"
"What can you do with a broken bey like that"
"Impossible , how could there be that much power left in that broken bey"
"What are you doing to my beautiful bey"
"Stop it stop it ; if you do that, if you do that ; that really hurts"
"I don't want it to hurt"
"I won't forgive, I will never forgive you"
"Destroy everything, break it, break it, smash it apart"
"Crush it, crush it ; into nothing 10"
"The bey-path that you have followed : confidence, friendship ; I'll crush all of it ; right here, and now"
"It's not over yet ; he's bey still hasn't been crush to nothing ; it still hasn't been broken enough for my liking"
"I'll tear your spirit apart, do you hear me ; so you won't be able to touch a bey ever again"
"So , it's you : Gingka"
"A Beybattle is for crushing your opponent until there is nothing left ; not even the Blader's spirit"
""I'm wrong?" Nonsenss ; everything you're saying is complete nonsense"
"And it your turn next ; do you hear me Gingka ; I will completely destroy your bey and your spirit ; just like I did to the others"
"I have to say ; I'm so very very happy Gingka ; I finally got a battle with you ; I've been looking forward to it so much ; the time when I can break you and Pegasus and all fun this will be ; I can't remember when it was ; but the first time I saw you, you were shining so bright ; it really was brilliant you know ; I was blinded by your talent ;; more than anything I wanted to take you down Gingka ; I wander, what will your face look like when I take you down, will it smirk then, as Pegasus breaks to pieces ; now go ahead and take your shot at me ; I am going to crush everything that you've got"
"You can dream"
"Hey there ; enjoying the sting of Serpent's real fangs"
"You see my Poison Serpent has two faces, two separated identities : up until now Serpent's spin track has been reversed, making it to defensive spin track that can deflect the opponent's attacks but when it flips over it turn into attack fangs that can rip apart anything"
"Now you'll see Poison Serpent's true power"
"What"s the matter ; is that all the power Pegasus has to offer"
"How is it ; is it painful ; ; even so, I won't allow you to be defeated with just this ; I want to see you struggle much harder to survive"
"Hun, no matter where you run, I will follow you ; Chase it Chase it Chase it into a corner"
"That's good keep incoming, the thought of that proud face of yours filling with fear gives me goose bumps ; I'm really really looking forward to it Gingka"
"All I want to see is your face as you whimper and cry, I wan to see your spirit crumble ; when I think about it I JUST CAN'T WAIT ANYMORE"
"Has your spirit become to grow cold with fear"
"More and more you'll get colder and colder ; you hear me ; and then you and Pegasus are going to turn to stone understand"
"Yes, turn to stone, turn to stone and then break apart ; along with your precious Pegasus"
"How does it fell ; frozen there ; just waiting for the moment when you will be smashed apart ; pretty scary hun"
"It must be so appall being that scared of me that you can't hold back ; and just want to scream and cry like a little baby"
"Now, let me hear it Gingka ; the wonderful sound of your scream"
"I get it ; you're so scared that you can't move your body at all ; but that no fun ; I want to see your face contorted ; you know, in fear, and a little sobbing would be welcome too ;; now I'm begging you, please turn your wimpy wittle face toward me ; that sad face that shows me your scare ;; ?!because I want to enjoy the fact that I'm the one who scares you the most"
"come on do it now"
"Hey, why are you smiling"
"The final, that's it ; even now I give you all my deadly poison ; tell me why ; why don't you fear me"
"How can you get excited"
"stop playing around you should be trembling and quiver in in fear OK"
"You're still smiling*"
"My fun comes from filling you guys with fear and despair"
"Break it, smash apart, see what true fear feels like when it shakes to your core"
'Reiji' is a common name given to people in Japan and 'Mizuchi' was a Dragon that looked like a snake.
He is the only character from Metal Fusion who did not make an appearance in Metal Masters. The only hint of him shown is a picture part of his lower body on the list of Japan's best bladers.
His Beyblade, Poison Serpent SW145SD, is the first to have a beast change.
He was the second blader to have a dark move, the first one being Ryuga.