Staff of the Letter Magus

As this artifact enters, choose a consonant other than N, R, S, or T. Whenever a player casts a spell, you gain 1 life for each time the chosen letter appears in that spell's name.

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6o4rj22c0jpb1h5ub5sazw.