For Clerics, Aerith Gainsborough and Rosa, Resolute White Mage are the obvious choices
Costing three ink, Winnie the Pooh, Having a Think has some pretty good stats and decent lore retrieval
A simple first build is a two-ink aggressive deck: lots of small evasive characters, a couple of songs for tempo, and a light removal package
Despite that, I still love Rootpath Purifier for the potential it represents
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Here is an example of a pretty all-in Emrakul, the Promised End decklist: Creatures (12) 1 Dragonlord Silumgar 1 Den Protector 1 Nissa, Vastwood Seer 3 Hangarback Walker 4 Deathcap Cultivator 2 Emrakul, the Promised End Planeswalkers (4) Lands (23) Spells (21) Obviously Nahiri, the Harbinger is a natural fit for Emrakul, the Promised End, and Patrick Chapin wrote last week about a bunch of different versions of Emrakul, the Promised End decks, many of which included the Boros planeswalker
