Jyggalag, Herald of Greymarch

You may not cast Jyggalag unless an opponent owns five or more creatures with Madness on the battlefield or in the graveyard.
When Jyggalag enters the battlefield, all lands on the battlefield lose all abilities and gain "{t}: Add {c} to your mana pool."
Whenever an opponent adds a colored mana to their mana pool, Jyggalag gains protection from that color until end of turn.