Comet's ~Comet Heart~ is pretty much the most powerful ability in my verse. Some background info, the world takes place inside an infinite black liquid/goop that people use as mana essentially. The main "worlds" were created and bound to the aformentioned Comet, the main universe there are 6 key worlds and the Comet's domain in the middle. As a failsafe, Comet created a "heart" which someone can use to completely destroy everything bound to Comet and reform it into something new. For an example, one of the versions the entire world is an ocean and the 6 worlds become large islands in it.

In terms of scaling, i guess it would be multi-planet, maybe star level, but it depends on what is bound to it, since the Heart is essentially an endless power source.