Injustice 1 was a different beast altogether, though; other than a few similar mechanics and legacy characters, they play almost nothing alike. Batman was strong in that game, definitely, but he shits on so many characters in this game, it's not even funny.
His trait allows him to punish any gap in the game, no matter how small, since he can release it while blocking. No remotely-negative move goes unpunished when he has a bat out. If you have any gap or are more than -2 (depending in spacing) he can then get a mindless, consequence-free full-combo punish. Now we see he even gets it off a throw tech.
And sure, let's say that's fine. But here's the issue; he always has access to a bat. When he calls bats, not only do they not go away, but he starts recharging his next set of bats while his current set is still out! Imagine if, once called, Dexstar just hung out until Atro expended all of his charges; if Atro never used any of Dexstar's moves, Dexstar would just be there, ready and waiting. And while out, Atro was already recharging his next use of Dexstar. Would that be considered unfair? Because that's how Batman's trait currently works.
I'm sorry, but I have to vehemently disagree; nothing about that is "fine".