Its often just turning a mana dork (think Dyad Arbor ) into something that ends the game
For example, the text of Valakut Exploration specifically says: You may play that card for as long as it remains exiled. The word play indicates that you can play lands that you exile with this ability
Despite it being an uncounterable creature that you can cast at flash speed, one of the most common things to do with Hullbreaker Horror is cheating it into play with a card like Polymorph
Then add these aura/enchantress payoffs: Ghostly Dancers, Hallowed Haunting, Sigil of the Empty Throne are the best token generators for Enchantress imo, don't need Ghostly Prisons when you have an army of 4/4 flyers that can also swing and win
Casting Aetherize at four converted mana cost is very overkill, but with Cyclonic Rift, you can just pay the normal one-generic, one-blue cost to deal with the problem instead