Oath of Kaya

Removal that arrives already paid for. Three mana buys three points of burn plus three life on the way in, a Lightning Helix stapled to a permanent, and the enchantment then sticks around as a deterrent. That second clause is the real design idea: it does not protect your planeswalkers by countering the attack or by padding their loyalty, it makes attacking them expensive after the fact. Any opponent who commits creatures to the walker pays two life and hands you two, a four-point swing that repeats every combat they choose to keep swinging. It is a soft lock rather than a hard one; the attack still resolves, the loyalty still drops, but the arithmetic grinds against the aggressor turn after turn. That structure suits the Oath cycle's premise, a set of enchantments built to reward decks that lean on planeswalkers as their engine, and this one is the most self-sufficient of the group because the entry trigger stands entirely on its own. Even in a shell with zero other planeswalkers, you still bank a full Helix, so the punisher half is upside rather than a prerequisite. Where other Oath enchantments only pay off once the walkers are actually on the board, this one earns its slot the moment it enters and keeps earning it if the opponent obliges.