Re: What fundamental thing would you change about the Hero system?
Multipowers do have an inherent limitation in them. And that is that the entire pool of the Multipower can only be in use in a very limited way at once. And with Ultra slots, those powers must be counted at their full value when used. And not divided, like standard multipower slots can be. It is a performance limitation on all powers in that framework.
But still, that performance limitation is one that is, by and large, barely felt in the coarse of actual play. And that's the problem. A limitation barely felt, by the strict definition of the design ethics behind the Hero System itself, should not grant such a huge amount of savings. That makes the Multipower broken when compared to those design ethics.
I do believe Multipowers can be fixed. But it will take what people consider a radical move. And that would be to include rules as a companion to it as to what limitations or advantages can be applied to the whole multipower and what can be applied to the slots. With the slots given heavy preference in the rulebook for advantages and limitations being applied to them at all. This will limit the point pyramid that currectly afflicts the Multipower.
The point pryamid effect is this: Advantages and limitations can be applied to two different levels of the multipower. The main pool and the single slots. But all of the slots automatically get a discount for being either a multi slot or an ultra. So that is three levels of discounts in the Multipower that can and does feed into each other. And in many ways, they can and do stack. Giving even more of a discount across the board. It's a design flaw. A very bad one. One that also exists in the EC. But the magnitude of the impact it has in the EC is far lesser.