Tidal Bore is a legendary major card out of the New mechanic pool. Returning Wave sends three waves 40° apart at 55% damage, each returning.

You can take it once · it only turns up when your Special ability can actually use it · it can be offered for 0 of the 34 abilities.

Only one card can reshape that ability this way — this one, or Standing Tide and Undertow Crest. Take one and the rest are gone for the run.