Sunblade Elf

Sunblade Elf gets +1/+1 as long as you control a Plains.
{4}{W}: Creatures you control get +1/+1 until end of turn.

Leyline Binding

Flash
Domain — This spell costs {1} less to cast for each basic land type among lands you control.
When Leyline Binding enters, exile target nonland permanent an opponent controls until Leyline Binding leaves the battlefield.

Kumena's Speaker

Kumena's Speaker gets +1/+1 as long as you control another Merfolk or an Island.

Gaea's Might

Domain — Target creature gets +1/+1 until end of turn for each basic land type among lands you control.

Chained to the Rocks

Enchant Mountain you control
When Chained to the Rocks enters, exile target creature an opponent controls until Chained to the Rocks leaves the battlefield. (That creature returns under its owner's control.)

Nishoba Brawler

Trample
Domain — Nishoba Brawler's power is equal to the number of basic land types among lands you control.