A melee secondary power set with a gimmick, powers scale up or down the size of your character depending on which ones you’re running. Make some toggles mutually exclusive.
I’m happy to flesh this idea out more/write up descriptions and whatever if this is something people express interest in, but for example: a T9 that unlocks two mutually exclusive toggles-
Supersize- doubles character current height, adds to max HP, +res all, +dmg, -def, -spd
Minuscule - reduces character height by 4x, +def all, -res, +recharge.