msem-instigator

Exile up to one target creature you control until your next end step. (Then exile this card. You may play the land later from exile.)

{T}: Add {C}.
{1}: Hoof Cliff Horngrove becomes a 2/2 Elemental creature until end of turn. It's still a land.
Menagerie — Whenever Hoof Cliff Horngrove becomes a creature, it gains your choice of +1/+1, flying, first strike, lifelink, trample, or haste until end of turn. This ability triggers only if there are five or more creature types among creatures you control.

As Humble Abode enters, choose a creature or planeswalker type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast spells of the chosen type.

Northrime Aurora enters tapped unless you played it from exile.
{T}: Add {G} or {U}.

Search your library for a land card, reveal it, then shuffle and put that card on top. (Then exile this card. You may play the land later from exile.)

{T}: Add {C}.
{2}, {T}, Sacrifice Rugged Expanse: Put a +1/+1 counter on target creature. It gains vigilance until end of turn. Activate only as a sorcery.

Slipsand Oasis enters tapped unless you played it from exile.
{T}: Add {W} or {B}.

Return up to one target creature card with mana value 1 or less from your graveyard to the battlefield.

Tinyvale Treetops enters tapped unless you played it from exile.
{T}: Add {G} or {W}.

Put a +1/+1 counter on up to one target creature. (Then exile this card. You may play the land later from exile.)