I like what Inquisitor Eisenhorn is doing, even if its a little hard to set up
A case could be made that there was no greater skill tester than Disrupting Scepter, but not because it forced your opponent to make hard decisions
As a result, Be Prepared is played in just about every single Ruby deck
Firstly with 40 card decks you can only play so many cool lands to go and fetch as you won't reliably have a forest of plains to ditch if you have too many non basics
We will all start saying Temur, Abzan, Mardu, Jeskai, and Sultai as a normal progression from playing with the set, so start now and make the transition easier
Additionally, Illuminator Virtuoso had its time in the sun as a top tier win condition in Boros Heroic decks for a while