Nyx Lotus

Nyx Lotus enters tapped.
{T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Kosei, Penitent Warlord

As long as Kosei is enchanted, equipped, and has a counter on it, Kosei has "Whenever Kosei deals combat damage to an opponent, you draw that many cards and Kosei deals that much damage to each other opponent."

Emerald Medallion

Green spells you cast cost {1} less to cast.

War Room

{T}: Add {C}.
{3}, {T}, Pay life equal to the number of colors in your commanders' color identity: Draw a card.