Literally starts falling apart and dying on the spot. Like I GET what 02 was going for there, he gains power from darkness and therefore light hurts him. The problem was that this had never been a thing before (aside from when he was Vamdemon and the SUN weakened him because you know...vampire) so it comes across as a complete asspull and the way it was presented was just completely cringe worthy.
It's also completely at odds with how seriously 02 took itself a lot of the time, given how much dark shit is in that season. Like Chimairamon wiping out whole cities of Digimon while the heroes look on in horror (and do nothing, useless shits), Ken's backstory, the Chocomon stuff in the Hurricane Touchdown movie and Oikawa's own backstory.
Nah forget all that, they just suddenly beat the villain with some Care Bears level shit.