It just does so much: You can protect key threats, apply early pressure, or use flying to sneak through the last few points of damage
MTG Playmats with Functional Zone Design Clean, Bold, Battle-Ready
However, permanent spells cast this way won't resolve until you're done casting spells, so the permanents they become can't be the target of spells cast this way
This puts a counter on the Terror, which makes Shalai and Hallar deal one damage to anything
What really sets this card apart is the mana flexibility: You can use mana of any type to cast creatures, which means color-fixing headaches are gone
If it's been played from your hand into your Bench, it's immune to damage until the end of your opponent's next turn