Balduvian Fallen

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.) Whenever this creature's cumulative upkeep is paid, it gets +1/+0 until end of turn for each {B} or {R} spent this way.

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6od87p9967pb1h9z1cbc1e.