Tendrils of Corruption

Tendrils of Corruption deals X damage to target creature and you gain X life, where X is the number of Swamps you control.

Dread Presence

Whenever a Swamp you control enters, choose one —
• You draw a card and you lose 1 life.
• Dread Presence deals 2 damage to any target and you gain 2 life.

Gate of the Black Dragon

Gate of the Black Dragon enters tapped.
{3}{B}, {T}: Seek a nonland card. Activate only once.
{T}: Add {B}.

Haunted Mire

({T}: Add {B} or {G}.)
Haunted Mire enters tapped.

Overgrown Tomb

({T}: Add {B} or {G}.)
As Overgrown Tomb enters, you may pay 2 life. If you don't, it enters tapped.

Soulhunter Rakshasa

Soulhunter Rakshasa can't block.
When Soulhunter Rakshasa enters, if you cast it from your hand, it deals 1 damage to target opponent for each Swamp you control.

Bontu's Last Reckoning

Destroy all creatures. Lands you control don't untap during your next untap step.

Druid Class

(Gain the next level as a sorcery to add its ability.)
Landfall — Whenever a land you control enters, you gain 1 life.
{2}{G}: Level 2
You may play an additional land on each of your turns.
{4}{G}: Level 3
When this Class becomes level 3, target land you control becomes a creature with haste and "This creature's power and toughness are each equal to the number of lands you control." It's still a land.

Rise of the Dark Realms

Put all creature cards from all graveyards onto the battlefield under your control.

Corrupt

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.