If they do, then youve eaten a counterspell and can cast your Omniscience next turn instead
This mostly seems like a good way to encore a bunch of your stuff back after a board wipe to win the game, and as such I think it's a lot better as a surprise from the 99 than sitting in your command zone
While I believe most decks should utilize the graveyard in some form, that doesnt mean you can stand to ignore it currently
You can cast cards from the top of your deck that have either one of those keywords, effectively giving you a free card in your hand at all times, assuming the top of your deck works with you a bit
If an exiled card you own is on an adventure, you can cast the creature
There is a 29.2% chance for a borderless, showcase equinox, or showcase fang rare card