Apothecary Initiate

A tax meter dressed as a one-drop. The trigger reads off any player casting a white spell, which makes the optional -for-1-life payment scale with the table rather than your own deck: in a board full of white mages, the meter ticks constantly, and you choose each time whether the marginal point of life is worth the floating mana. That conditional payment is the discipline here. Unlike the lifegain-per-spell engines that fire for free, this one charges you every increment, so it never spirals on its own and never demands an answer the way a runaway engine would. It is a slow drip built for an era that wanted color-matters payoffs without runaway value, and the body is exactly as fragile as a 1/1 should be when the real card is the standing trigger. The Kithkin Cleric framing fits: a small white creature whose contribution is incremental healing rather than combat. As a piece of incidental lifegain, it rewards a board already saturated with white spells and asks for spare mana to convert that activity into a thin, steady cushion.