Hand of Fate 2

This one is easy once you've unlocked Veles as a companion by completing The Servant challenge. The Emperor and The Mapmaker are 2 ideal maps for getting this done because they are so large. Enter the camp menu and use Veles' ability which should typically reveal 2 encounters. Sacrifice 15 health to instantly revive him, then rinse and repeat 15 times. Forfeit the challenge when your health gets too low so you can continue.