Shouldn't do a lot of damage anyway since Brain Freeze stop taking damage after some hits. I've tried it different times, the first days after the last update I was able to do tons of damage, then some days after her bb3 was useless against her since the damage was 0, and then till the beginning of this week I was able to almost one kill (somethimes even one shot her) 30k Brain Freeze after 50+ streak every time I fought her.Could be because of that double damage when enemy has full blockbuster. It's a powerful boost.
Anyway I've fight the same opponent two times in a row in a fight prize a couple of weeks ago, so same characters, same abilities, same conditions, both times Brain Freeze was the last opponent with full hp with no buffs or debuffs (me too), both of us with fully charged blockbuster, the first time I killed her in one hit, the second time she takes no damage at all. The only thing that changed is that I played the first fight just after the day resetted and the second the day after.