For kendrick, crush him totally. Annihilate him. Another music video and a final death blow, especially if you can back up your claims. You will be cemented as the unanimous GOAT of your era if you aren't already.
If you're drake, it's time to start playing defense PR wise. Rapping isn't going to help I don't think, it's time to have receipts put out there clearing your name of these allegations. Disappear for awhile and then pop out on some afrobeats or UK shyt before trying to come back in full force.
You could try to go business as usual and try to make regular music but that's going to be hard, you'll maintain numbers for awhile but eventually you'll start getting did like DaBaby and taken off of gigs, festivals, etc. and then you'll slowly bleed out.