Tiger-Seal You have to be all in on the draw-2 theme, but Tiger-Seals not too bad of a payoff for doing that
I didnt want to play Whipflare just to beat one deck, so I started playing Illness in the Ranks in that slot instead mostly because Illness is also effective versus Splinter Twin (the copies are tokens, so Deceiver Exarch has zero power and Pestermite simply dies)
The other mention here is one that is powerful in basically any deck: The One Ring
Not only is this the exact card that every combo deck wants, its an instant that will occasionally just win you the game against an opposing battlefield sweeper or alpha strike
Hypnotic Specter Hypnotic Specter used to be a nasty black creature, but both threats and removal have become more efficient in our modern era of Magic, pushing this specter to the side
Returning Mechanics Future Sight introduced a ton of new mechanics, but it also found new design space for old mechanics