Heart of Bogardan (WTH)

Cumulative upkeep (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.)
When a player doesn't pay Heart of Bogardan's cumulative upkeep, Heart of Bogardan deals X damage to target player or planeswalker and each creature that player or that planeswalker's controller controls, where X is twice the number of age counters on Heart of Bogardan minus 2.

Legalities

• brawl: banned
• commander: legal
• legacy: legal
• modern: legal
• pauper: legal
• pioneer: banned
• standard: banned
• vintage: legal

Rulings

• 2008-04-01:

  In other words, if you sacrifice Heart of Bogardan rather than pay its cumulative upkeep, X is equal to the amount of mana last spent to pay its cumulative upkeep.

Links

• Scryfall
• Gatherer
• Cardmarket
• TCGplayer
• Card Kingdom