I highly like this idea. Main question is how will magic work in this setting. I would suggest using one or both of two ideas:

1. Very animistic/druidic magic. Not so much calling lightning or moving mountains as asking the lightning nicely to strike there rather than here. Also much more emphasis on buffs and empathy.

2. Extremely volatile and haphazard arcane magic. The rare few who have access to arcane spells generally are either sorcerors who have no clue how to direct the magic flowing through them or wizards who have discovered arcane scrolls in some of the fey ruins and thus have a haphazard assembly of spells they don't fully understand. Expect a lot of spells misfiring or going off spontaneously.