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.

Glaciers

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

Farseek

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

Conversion

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

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.

Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

Lush Growth

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