Sacrifice after III.) I, II Search your library for a legendary creature card, reveal it, put it into your hand, then shuffle
The "Other" category encompasses a diverse mix of archetypes, including Mono-Black Conqueror, Boros Enchantments, Naya Burn, Esper Reanimator, Selesnya Tokens, Orzhov Midrange, Golgari Midrange, Mono-Black Demons, Dimir Reanimator, Orzhov Lifegain, Five-Color Legends, Mono-Green Aggro, Surprise Ramp, Rakdos Sacrifice, Boros Tokens, Mardu Pact, Jund Demons, Mono-White Angels, Mono-Blue Tempo, and many others
An alternative strategy, which I used to prefer, involves running five to six exile target artifact effects in the 75, and aggressively Sinkholing the opponent while developing Monarch and Terror
Impulse gets you through your deck quickly, allows you to quickly search for an answer to an impending problem, and does it all so effectively that almost any blue deck capable of running Impulse in any given environment has done so without hesitation
If any of the other Elder Dragons catch your eye, its not hard to support most of them
