Command Tower

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

Mana Web

Whenever a land an opponent controls is tapped for mana, tap all lands that player controls that could produce any type of mana that land could produce.

Atzal, Cave of Eternity

(Transforms from Journey to Eternity.)
{T}: Add one mana of any color.
{3}{B}{G}, {T}: Return target creature card from your graveyard to the battlefield.

Journey to Eternity

Enchant creature you control
When enchanted creature dies, return it to the battlefield under your control, then return Journey to Eternity to the battlefield transformed under your control.

Journey to Eternity // Atzal, Cave of Eternity

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.

Wound Reflection

At the beginning of each end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.