Tool
Damage calculator
Champions does not use EVs or IVs. You get 66 stat points to spread, with no more than 32 in any one stat, plus a stat alignment that shifts one stat up and another down. This calculator works the way the game does.
Final stats here are estimates
The 66 point budget and the 32 per-stat cap come straight from the game's help text, and the damage formula is the standard one. What Champions does not publish is how stat points convert into final stats, so that conversion is fitted rather than confirmed. Percentages are directionally right and good for comparing options, but treat exact knockout thresholds as close rather than certain.
Only damaging moves Mega Greninja can legally learn in Champions. The item list is the 22 whose in-game description states a damage modifier.