Blood Researcher

Lifegain-matters payoffs usually ask for a lot of setup: a dedicated shell, a life-total engine, and the patience to wait for the counters to add up. This one collapses the ask. The trigger keys off the event, not the amount, so a single small drain or a Soul Warden ping earns a +1/+1 counter exactly like a big swing does; a fair midrange deck's incidental lifegain becomes growth instead of just stabilization. The pairing of that growth with menace is what turns a slow green-black beater into a clock: a body that gets harder to block profitably the exact moment it gets bigger, so a couple of lifegain events leave the opponent staring down a threat that two blockers can no longer trade with cleanly. The design sits at a familiar green-black intersection, and the Vampire and Druid on the type line telegraph both the aristocrats-drain and counters-synergy homes it wants, but the loose trigger keeps it from demanding a build-around. A little lifegain makes it a threat; a lot makes it a problem the opponent has to answer while it is still small enough to kill cheaply. What keeps it honest is that the counters do nothing on their own: without lifegain it stays a 2/2 with menace that trades down. It rewards decks already gaining life for other reasons rather than decks that gain life to feed it.