Since theyre also creatures, you cant tap them for mana the turn they are created, but with any way to give them haste, it could be devastating
Fetchlands like Misty Rainforest are great ways to reset the top of your library to get a fresh look with The Fourth Doctor, but Id also recommend trying out cards like Bant Panorama and Shire Terrace which enter the battlefield untapped and tap for colorless mana in the early-game, and then you can cash in for a basic land and shuffle your library later when you need it
Faceless DevourerFaceless Devourer has to target a creature with Shadow, but we'll get to that later
Spells you cast cost 1 less for each card your opponents have drawn this turn
Some immediate creatures you could bring back include Kroxa, Titan of Death's Hunger, and Blood Artists for maximum value
Perhaps it's a way to represent levelled-up magic, like the Thunder-Thundara-Thundaga progression that black mages use