Well I finally burnt through my nearly 6000 energy I had saved up from daily logins and not playing for a few months. Got 3 6 star and 4 5 star heroes, tons of mastery materials and equipment upgrades, not bad.
Now I actually have to budget my energy for farming bios though, which is a bummer. I ran out yesterday without getting my full allotment of Iron Man and War Machine. I should probably concentrate on characters I'm closest with, but I feel wasteful if I'm not doing the harder to get ones like Thor on a daily basis.
Either way, I'm still nowhere near able to beat a WB, or even make it more than a little over halfway on the Villain Seige. The difficulty in this game is very uneven.
Does anyone have a guide on the ISO system? So far I've just been putting whatever on whoever (I at least check to make sure I'm not putting energy attack bonus on physical characters), but I have no idea if i'm being completely ineffective. The game doesn't explain much of it.