Board Thread:Event Help/@comment-32803230-20171014002456/@comment-33728484-20171015100145

SSJ2 Gohan because unlike SSB Vegeta he won't need any red orbs to super attack. Plus, SSB Vegeta gives himself a +100% ATK boost and he has a Supreme SA (+250%), while SSJ2 Gohan gives himself a +70% ATK boost but he has an Immense SA (+280%).

The difference between Supreme and Immense becomes even bigger if you happened to raise their SA (SSB Vegeta goes from +250% to +430% at SA10, while SSJ2 Gohan goes from +280% to +505%)