M:tG card similarity search
· Artifact
Apex Observatory enters the battlefield tapped. As it enters, choose a card type shared among two exiled cards used to craft it. {T}: The next spell you cast this turn of the chosen type can be cast without paying its mana cost.
| Name | Mana | Type | Text | 
|---|---|---|---|
| Umori, the Collector | 2B/GB/G | Legendary Creature — Ooze | 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 the battlefield, choose a card type. Spells you cast of the chosen type cost {1} less to cast. 4/5 | 
| Morophon, the Boundless | 7 | Legendary Creature — Shapeshifter | Changeling (This card is every creature type.) As Morophon, the Boundless enters the battlefield, choose a creature type. Spells of the chosen type you cast cost {W}{U}{B}{R}{G} less to cast. This effect reduces only the amount of colored mana you pay. Other creatures you control of the chosen type get +1/+1. 6/6 | 
| Aminatou's Augury | 6UU | Sorcery | Exile the top eight cards of your library. You may put a land card from among them onto the battlefield. Until end of turn, for each nonland card type, you may cast a spell of that type from among the exiled cards without paying its mana cost. | 
| Cosmium Catalyst | Artifact | {1}{R}, {T}: Choose an exiled card used to craft Cosmium Catalyst at random. You may cast that card without paying its mana cost. | |
| Counterlash | 4UU | Instant | Counter target spell. You may cast a spell that shares a card type with it from your hand without paying its mana cost. | 
| Urza's Incubator | 3 | Artifact | As Urza's Incubator enters the battlefield, choose a creature type. Creature spells of the chosen type cost {2} less to cast. | 
| Progenitor's Icon | 3 | Artifact | As Progenitor's Icon enters the battlefield, choose a creature type. {T}: Add one mana of any color. {T}: The next spell of the chosen type you cast this turn can be cast as though it had flash. | 
| The Ringhart Crest | 1G | Legendary Artifact | As The Ringhart Crest enters the battlefield, choose a creature type. {T}: Add {G}. Spend this mana only to cast a creature spell of the chosen type or a legendary creature spell. | 
| Reflections of Littjara | 4U | Enchantment | As Reflections of Littjara enters the battlefield, choose a creature type. Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.) | 
| Serra's Emissary | 4WWW | Creature — Angel | Flying As Serra's Emissary enters the battlefield, choose a card type. You and creatures you control have protection from the chosen card type. 7/7 |