That's the perfect scenario for us and him, and City...
Sevilla would be a weird one but he'd get to stay in the CL. However if Rico is as good as
@Zatara says he is(...) then would he be a guaranteed starter.
Everton - he gets to stay in the area, he will be on equal wages (albeit City would probably pay half his wages if he went to Sevilla), stay in the Prem - guaranteed first choice (as good as Stek was the other day) and Koeman doesn't require his keepers to be brilliant with his feet. Also knows that he will be part of what should now be an experienced and more organised defence.