This guide will help you with the best of them, blue, but the world is your oyster
For example, Bite of the Black Rose forces your opponents to discard two cards in the event of a tie
Here's an easy example: the ancillary card slot could contain a very expensive Arcane Signet or a just-as-expensive Chulane, Teller of Tales, or it could contain a common gain land like Thornwood Falls
A regenerated creature keeps all its enchantments on it, so Molting Snakeskin remains useful as long as you can pay for the ability
Jokes and lore aside, it can cast noncreature spells from your graveyard whenever it mutates
Heres a bit of a left field deck suggestion: Nine-Fingers Keene wants to get as many different Gates onto the battlefield as possible, so having an instant to assist in that mission will be a sneaky inclusion