There are some good cards already in the deck that you should add more of
Double-faced cards were in the set from the beginning, as they're the most effective way of showing how heroes and villains have big story-related changes, and Sephiroth becoming the one-winged angel was necessary
Gramma Tala: Storyteller, Mickey Mouse: Detective, and One Jump Ahead are all key cards for ramping up in the Sapphire/Steel deck, with each offering its own method of adding to the inkwell at a low cost
I wouldnt tunnel in on Grixis too early, but if you are drafting blue/red and havent seen any good payoffs, consider picking black removal and going the Grixis direction
She also gets power increases based on the mana spent on your spells, rather than a flat rate like most similar creatures
nothing else doubles up equipment triggers without some additional qualifier (it has an enters ability for Panharmonicon, a saboteur ability for Felix Five-Boots, etc.)