Tahngarth can't be blocked by more than one creature. Whenever an opponent attacks with one or more creatures, if Tahngarth is tapped, you may have that opponent gain control of Tahngarth until end of combat. If you do, choose a player or planeswalker that opponent is attacking. Tahngarth is attacking that player or planeswalker.

Berzerker — Khârn the Betrayer attacks or blocks each combat if able. Sigil of Corruption — When you lose control of Khârn the Betrayer, draw two cards. The Betrayer — If damage would be dealt to Khârn the Betrayer, prevent that damage and an opponent of your choice gains control of it.

({T}: Add {R}.)

At the beginning of your upkeep, put two descent counters on this enchantment. Then each player creates X Treasure tokens and this enchantment deals X damage to each player, where X is the number of descent counters on this enchantment.