Vault of Champions

This land enters tapped unless you have two or more opponents.
{T}: Add {W} or {B}.

Mathas, Fiend Seeker

Menace
At the beginning of your end step, put a bounty counter on target creature an opponent controls. For as long as that creature has a bounty counter on it, it has "When this creature dies, each opponent draws a card and gains 2 life."

Windswept Heath

{T}, Pay 1 life, Sacrifice this land: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

Verdant Catacombs

{T}, Pay 1 life, Sacrifice this land: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.