Command Tower

{T}: Add one mana of any color in your commander's color identity.

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Spore Frog

Sacrifice Spore Frog: Prevent all combat damage that would be dealt this turn.

Merciless Executioner

When Merciless Executioner enters, each player sacrifices a creature.

Caustic Caterpillar

{1}{G}, Sacrifice Caustic Caterpillar: Destroy target artifact or enchantment.

Sol Ring

Fleshbag Marauder

When Fleshbag Marauder enters, each player sacrifices a creature.

Meren of Clan Nel Toth

Whenever another creature you control dies, you get an experience counter.
At the beginning of your end step, choose target creature card in your graveyard. If that card's mana value is less than or equal to the number of experience counters you have, return it to the battlefield. Otherwise, put it into your hand.