Ghostly Prison is perhaps the most hilarious artwork Ive ever seen in Magic, but the card itself can be rather annoying
Historically good decks that dont exist in large numbers in Standard right now include Mono-Red Aggro, Big Red, Mono-White Aggro, W/R Aggro, Reanimator, Jund Midrange, Bant Hexproof, Bant Control, G/W Aggro, and B/R Aggro
I get the idea is to build out your deck over time and these are the easiest place to start, but these cards are too important to leave out
open up a card to attack for more summoning power or use an ability at the risk of having more cards on the table
However, with Rhystic Study on your side, you should have no trouble drawing into an answer for whatever new threats are sent your way
It can be a great Voltron commander or a simple support piece, so the cards in the 99 get the job done