There's no need for "no mana cost" or "unlimited skills"... Y'all pretty hilarious.
The fact is, once you're in a match, the game server can already calculate and predict whether your combat power is sufficient to win that game.
That's why if you abuse the mod so badly, it turns out "battle results verification error". Just grind your BP and be patient, this game is mostly a p2w which you need many times to spend on it.
Edit: Didn't get ban since the start of the game, half a month like 17?or18 days until now.