Lifegain leans heavily on triggering lifegain with Hinterland Sanctifier, Case of the Uneaten Feast, and Haliya to fuel payoffs like Amalia Benavides Aguirre, which explores whenever they gain life and can wipe the other creatures once her power reaches exactly 20, so attacking their resources and shutting off lifegain is key. Grievous Wound goes on the opponent: it stops them from gaining life, which turns off Amalia's trigger and Ajani Resolute's loyalty growth, and whenever they are dealt damage they lose half their life, rounded up, which makes your attacks and burn much more punishing. Duress proactively strips a noncreature, nonland card like Erode, Case of the Uneaten Feast, Ajani Resolute, or Lunar Convocation before it resolves (it can't take their creatures, such as Liliana the Faultless). Deadly Precision's extra cost and Callous Inspector's fragile body are less impactful than disrupting their core engine.