Having a mystery creature suddenly become an all-but-uncounterable board wipe isnt always going to be useful, but when it is, itll be great
(x1-x2) Lightning Storm (Optional) Destroys Attack Position or Spell/Trap Cards from opponents side of field
Without worrying about win conditions or mechanics or anything like that, let's imagine a simple units-on-the-board card game
If this card would be destroyed by battle, destroy that equipped monster instead
There are a ton of very powerful WizardsArcanis the Omnipotent, Memnarch, Ambassador Laquatus, Trinket Mage, Niv-Mizzet, the Firemind, Teferi, Mage of Zhalfir, Venser, Shaper Savant, and more
Then, if you ever get up to the 7 mana for its activated ability, youll probably just win the game