Omega Phi

In this world power is derived through Stardust, me st people however have inert Stardust which does nothing. However if someone undergoes a very specific situation it may energize their Stardust allowing them to gain powers that are tied to what energized their Stardust. (You can come up with your own powers and origin but now). This leads to Omega Phi, who isn't of this world, she's from the in-between, a place beyond the Universe. She gets her power from elsewhere and not from Starsust which allows her greater power than effectively anyone else. This has given her a massive God Complex. She's never lost to anyone and has built up an infamous reputation as a destroyer of worlds. However maybe you could finally put an end to her rampage.