As long as you keep your abilities/buffs up and in constant rotation, you literally cannot die thanks to the new shield gating mechanic when coupled with Harrows inbuilt shield strengths from his Condemn ability and his passive, coupled with the insane attack speed and life steal bonus Penance gives to your melee and he is unstoppable. To increase his immortality even further you can synergy him with the [Rakta Dark Dagger], but he can survive steel path anything if you play him well without it, so up to you.