Glaciers

At the beginning of your upkeep, sacrifice Glaciers unless you pay {W}{U}.
All Mountains are Plains.

Blood Moon

Lush Growth

Enchant land
Enchanted land is a Mountain, Forest, and Plains.

Conversion

At the beginning of your upkeep, sacrifice Conversion unless you pay {W}{W}.
All Mountains are Plains.

Naked Singularity

Cumulative upkeep {3} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
If tapped for mana, Plains produce {R}, Islands produce {G}, Swamps produce {W}, Mountains produce {U}, and Forests produce {B} instead of any other type.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Last Stand

Target opponent loses 2 life for each Swamp you control. Last Stand deals damage to target creature equal to the number of Mountains you control. Create a 1/1 green Saproling creature token for each Forest you control. You gain 2 life for each Plains you control. Draw a card for each Island you control, then discard that many cards.

Dominaria's Judgment

Until end of turn, creatures you control gain protection from white if you control a Plains, from blue if you control an Island, from black if you control a Swamp, from red if you control a Mountain, and from green if you control a Forest.