If I use Combusken's(GE) Bulk Up attack, then on the next turn I evolve Combusken into Blaziken, will Bulk Up give Blaziken +30 to each of it's attacks?
Blaziken is not Combusken.
Combusken is no longer in play.
Aside from that, Evolving gets rid of all effects, whether they are good or bad.
No bonus damage.
