Quick one today--gotta get ready for Mothers' Day.
One of the things that ICONS doesn't do well as written is powers that adjust abilities. Yes, it has Ability Boost, but I'm thinking of things like a villain who drains an ability or or a suit of armor that "doubles his Strength"--or increases it by +1.
The biggest problem with using Ability Boost is that the ability level drops by one after its use. For whatever reason, there is no Extra that buys this off, though you can make one up. The other is that by default it lasts for level number of panels. (There is an Extra to buy that one off.)
Ability Increase can be used for this sort of thing, with the Source Limit, but the game also lets you say, "As a normal, he's Strength 3". I don't want to get too far into having rules for everything because that way lies the Hero System. It's useful for suits of powered armor, though, without having to go, Transform: Grants wearer the following powers...
How do you drain abilities? Nullification doesn't explicitly touch abilities under 7 (they're not powers), but you could create an extra that will let it. Something like, oh, Nullification Extra: affects abilities, Limit: Extra only lets you create the equivalent of Champions' Will Drain. I would probably let it affect Stamina by default (it does in the comics, I think).
What else is tough to do in ICONS?