Steel (grey) - this ink will focus on " brute force ", with a focus on attacking with your Characters, and effects that relate to challenging and combat
Even if you're in mono-blue, unless you're a full-on "there's only so much fun in a game of Magic, and I'm here to have all of it" person and are playing 40 CounterspellCounterspells, there's now a better option in Thunderclap DrakeThunderclap Drake
And then you are in the color of Blue artifact tutors like Trinket Mage and Fabricate which will now search up anything
Abilities that kill creatures after they damage you have proven unworthy as general strategies in the past, but on a three-mana card that would have cost three mana anyway, this is by far the cheapest such an ability has ever been
You might want to focus on removal spells (like [c]Fateful Absence[/c]), counterspells (like [c]Saw It Coming[/c]), and board clears (like [c]Doomskar[/c])