Cavern of Souls - Modern Masters 2017 (MM3)As Cavern of Souls enters the battlefield, choose a creature type. {T}: Add {C}. {T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Whenever you cast a spell

Order of Redeemed Souls

Beware the generosity of demons

You may play an additional land this turn

A wild tale

giant-sized rubble tokens to change your boards and Zombivor rules

{T}: Untap target attacking creature

Death Aspect enters the battlefield

Each creature you tap while casting this spell pays for {1} or one mana of that creature's color

put a +1/+1 counter on Soulherder

Soul of the Wild's power and toughness are each equal to the number of lands you control

When Cavalier of Dawn dies