The biggest difference here is that whilst Ayara gains you life, and in doing so buys you more time to take advantage of your engine, Priest makes mana whilst sacrificing creatures thus speeding up your deck in the process
His small size allows him to observe events in all the realms and prize out secrets which he then carries back to Esika
Oath of Gideon will give you creatures and set you up for using Elspeth, Knight-Errant, or Elspeth, Suns Champion a little later in order to make more tokens
Finally, the data that Rekognition sends back gets processed by another Python script that looks up the identified cards on the TCGplayer API to find their price
Sorcery speed hurts this card, but at two mana it isnt too inconvenient
List of Stuff Worth Splashing Commons The main commons youd splash are unconditional removal spells like Sephiroth's Intervention and Fate of the Sun-Cryst