A card like this one will likely be in the next block to hose all those ETB Energy cards in Kaladesh
If they're in sleeves (single or double), the standard Charizard Card Binder fits 360 of them
Goto the mailbox and they will give you special tape to seal the box up completely
However, there are a few multi colored decks that are running mono red draw in both the main deck and the sideboard recently
Combined with Exploration or Fastbond, the Horn quickly becomes an engine from which you can draw three, four, five, or more cards a turn, at no cost
The two most played removal spells by a large margin were Lightning Bolt and Path to Exile the former of which could be played early but could only kill small creatures, while the latter could deal with any creature but was punishing to play in the early turns of the game