Essence Warden

Soul Warden in green, and that color-shift is the whole point: a creature-trigger lifegain stapled onto a one-drop body, ported from its white original into a color where Elf Shamans and token swarms make the trigger fire far more often than white weenie ever could. The ability counts every other creature that enters, yours or an opponent's, by any means: cast, blinked, copied, reanimated, made as a token. That breadth is what turns it from incidental gain into an engine. In a deck built on going wide (Elf decks, populate strategies, anything that floods the board with bodies), each new creature is another point, and a single board-refill can swing a life total by double digits in one turn. The 1/1 frame does no combat work and is not asking to; it is a permanent that converts board development into life, and it stacks, so two copies double every trigger. What makes it durable is that the payoff scales with whatever your deck was already trying to do. You do not build around the lifegain; you build a creature deck and the lifegain falls out of it, which is exactly why green's go-wide archetypes have leaned on this template across decades while burn-based aggro has never found a clean answer to a Soul Warden effect that keeps the gas coming.