Umori, the Collector

Companion — Each nonland card in your starting deck shares a card type. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
As Umori, the Collector enters, choose a card type.
Spells you cast of the chosen type cost {1} less to cast.

Elder Deep-Fiend

Flash
Emerge {5}{U}{U} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, tap up to four target permanents.

Swamp

Distended Mindbender

Emerge {5}{B}{B} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, target opponent reveals their hand. You choose from it a nonland card with mana value 3 or less and a card with mana value 4 or greater. That player discards those cards.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Arboreal Grazer

Reach
When Arboreal Grazer enters, you may put a land card from your hand onto the battlefield tapped.

Foul Emissary

When Foul Emissary enters, look at the top four cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
When you sacrifice Foul Emissary while casting a spell with emerge, create a 3/2 colorless Eldrazi Horror creature token.

Lashweed Lurker

Emerge {5}{G}{U} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, you may put target nonland permanent on top of its owner's library.

Fierce Empath

When Fierce Empath enters, you may search your library for a creature card with mana value 6 or greater, reveal it, put it into your hand, then shuffle.

Farhaven Elf

When Farhaven Elf enters, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Opulent Palace

Opulent Palace enters tapped.
{T}: Add {B}, {G}, or {U}.

Island

Foreboding Landscape

{T}: Add {C}.
{T}, Sacrifice Foreboding Landscape: Search your library for a basic Swamp, Forest, or Island card, put it onto the battlefield tapped, then shuffle.
Cycling {B}{G}{U} ({B}{G}{U}, Discard this card: Draw a card.)

Forest

Elvish Rejuvenator

When Elvish Rejuvenator enters, look at the top five cards of your library. You may put a land card from among them onto the battlefield tapped. Put the rest on the bottom of your library in a random order.