Named after Cell, this guy shares a lot of his parent’s moves, as well as his own unique Step Up Attack.
– Finger Beam (beam, 10cc, 15pow, 100acc)
– Kamehameha (beam, 16cc, 20pow, 100acc)
– Step Up Atk (melee, 19cc, 25pow, 100acc)
– S.Beam Cannon (beam, 21cc, 30pow, 75acc)
– S.Kamehameha (beam, 23cc, 30pow, 100acc)
– Resurrection (item, 10cc, recover health, 100acc)
– Taiyoken (dodge, 5cc, Avoid Melee, -)
– Barrier (dodge, 5cc, Avoid Beam, -)
This arsenal of moves makes Cell Jr actually usable, despite his low stats. I would not recommend Kamehameha (not enough power to justify the cc) or S.Beam Cannon (accuracy too low), but all the other options are pretty solid. Keep in mind that his low stats make Finger Beam not as damaging as for other characters, but feel free to use it if you prefer to use a low-cost strategy.
Resurrection, Taiyoken and Barrier make for excellent defensive cards if you time them well. I recommend only putting one of them in your Limits at most, though, depending on who your opponent is.
DBZ:LSW, your one and only stop for everything to do with Dragonball Z Legendary Super Warriors on the Gameboy Color 
Definitly one of the hardest characters to build, i personally use pure ki or str builds, trying to balance stats would be a mistake and harder to play considering the low stats it has by default, but with the variety of moveset is pretty cool to play.