Herald's Horn
53PlayableArtifact
The Lost Caverns of Ixalan Commander
2HG Rating
53/100
Plays about the same in 2HG as it does in any other format.
No 2HG-specific rules fire on this card — it plays much the same here as anywhere else.
Ratings start at a neutral 50 and are adjusted by rules derived from 2HG's structure — shared 60 life, shared turns, two opponents. They'll be recalibrated against real play rates once teams start submitting decklists.
Oracle text
As this artifact enters, choose a creature type.
Creature spells you cast of the chosen type cost 
less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.
Legality
Plays well beside it
Fits the same colour identity — good candidates for your teammate's deck.
Suggestions are characteristic-based for now. Once teams submit pairings, this becomes a real co-occurrence score: played in X% of teams whose partner deck runs Herald's Horn.