just because it's dead doesn't mean it isn't there
it just can't go about making stupid decisions like "let's protect every baby pomp with an energy bubble that they can freely manipulate without considering that most babies quickly go insane with power and oppress innocent civilians"
and anyways there are several pomps outside the universe, in exoversal space are the two fussbudgets and beyond that is the waiting room, which contains a whole host of characters
the in-your-face pomp and the s-ranks are capable of travelling in and out of the universe, the latter use their powers to get across the universal boundary and the former just breaks through it (which incidentally is how he killed it in the first place)
also regularly visiting the edge of the universe are the lightspeed pomp, who does his daily runs around its circumference, and a whole armada of babies trying desperately to bring it back to life so they can get their powers back (the in-your-face pomp regularly kills this group and they regularly regroup and return)