Drowned Catacomb

Drowned Catacomb enters the battlefield tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Blightning

Blightning deals 3 damage to target player or planeswalker. That player or that planeswalker's controller discards two cards.

Lightning Bolt deals 3 damage to any target.

When Archaeomancer enters the battlefield, return target instant or sorcery card from your graveyard to your hand.

Lonely Sandbar enters the battlefield tapped.
{T}: Add {U}.
Cycling {U} ({U}, Discard this card: Draw a card.)

Electrolyze deals 2 damage divided as you choose among one or two targets.
Draw a card.

Defender
When Mnemonic Wall enters the battlefield, you may return target instant or sorcery card from your graveyard to your hand.

Dragonskull Summit enters the battlefield tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

At the beginning of your end step, you may exile target creature you control, then return that card to the battlefield under your control.

Draw three cards, then put two cards from your hand on top of your library in any order.

Sulfur Falls enters the battlefield tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.