Hal had absorbed chronal energies left after COIE to destroy time stream. Here he destroys an entire universe by opening an entropy rift. Later Extant says there are other entropy rifts he was not responsible for.
Later the power of CPB were used to give Kyle Rayner the power of Ion where he was literally omnipresent throughout time and space and able to alter reality on fundamental level. Ion later exhausted his power returning his power to CPB and resurrecting the Guardians.
A full-powered Prime's heat vision hits a Guardian, and though it wounds him, it is stopped by the Guardian's shoulder.
This is particularly notable given how powerful Prime's HV was earlier in the story in Sinestro Corps: Superboy Prime, when it shot right through Superman's chest while Prime was heavily weakened and deprived of sunlight.
Guardians battle and stalemate Nekron, stop galaxies from destruction, defeat Krona after Nekron is distracted by Hal, seal the rift between universes and return the whole universe to its original state when it was near destruction. Beastly feats.
Guardians vs Guy Gardner with Hand of Krona and later entire GLC, Larfleeze, White Lantern Kyle, Red Lantern Corps with Manhunters. All of this while controlling almost a third of the universe with their minds.