You'll want to cut six removal spells (leaving three Hero's Downfalls to kill Planeswalkers and as insurance against a surprise creature off the opponent's sideboard)
Mono-blue is too restrictive a color for this to feel impactful
Cauldron Familiar is a particularly cool card, and I find myself using it in various popular formats, including Pauper
Why go for Japanese versions
(Players dealt combat damage by them also get a poison counter.) Corrupted At the beginning of your upkeep, if an opponent has three or more poison counters, choose a creature you control, then draw cards equal to its total toxic value
These sets, while not the most popular or the most financially viable for WotC, serve an important purpose in reminding us that Magic is, ultimately, just a game