People were weirdly low on it when it came out because it was four mana, but so many people are low-mana-value-pilled that they miss out on obvious potential
Theres a ton of applications for this: you can elk your own cards once youre done with their effects, you can elk the Food token he makes, and best of all, you can elk your opponents big creatures and artifacts essentially making Oko a persistent answer to that your opponent will need to play around
The other big question for this deck is whether theres any chance of running Ego Drain, the third big Faerie support card from Wilds
It only adds colourless mana to your mana pool as standard, but youre rarely going to be playing it as Echoing Deeps
Having a large chunk of the metagame that is simply a bye is a big deal and I really like that aspect of Hexproof
Whole religions, like the Church of Avacyn, were built up around her