Phlegra seems like a giant nation where you'd almost never want to recruit giants.
Tyrant and Elder Cyclops are very niche. You might want one cyclops for forge duty and a tyrant is your only D access for hounds of twilight, but you're not likely to go for them in combat. The tyrant doesn't really have great paths for thugging (E is good but not really enough by itself, so they're only decent at phoenix pyre if you pump them full of reinvig and accompany an army or at least mouflon blockers) and the cyclops has even worse stats and no gear, despite a chance at A2 for mistform, and they're too expensive to compete with your other mages, not least because oppressors are communion masters so you'll never need another high path unit, just send some shackled mages along with them for less cost, less fatigue per actual caster, and more versatility.
You'll also recruit a few shepherds to get sheep, whose supply bonus is nice and they're free of upkeep and a decent distraction + evo-catcher and the shepherd is already decently priced for a mage, even if it's just N1. But the big guys aren't nearly worth 300+ gold.
The main weakness of the nation, aside from the giants being a trap, is that your troops are terrible. I think you'll want an awake expander for that reason alone. But at least they're not hard to spam. And if you go the mouflon route, those are decent blockers for a short time, they can even do a bit of damage, which makes them well worth it if you consider that all they cost is the shepherd's upkeep as he generates them. Hounds of Twilight would solve the problem a bit if only they were more spammable. But requiring four gems and one Tyrant's turn per each, their role is gonna be very niche. Mix them with your mouflons (sheepdogs!) for the fear effect, maybe.
tl;dr: Basically Marverni with elemental paths instead of astral, except worse because your mages and forts cost more and your freespawn blockers aren't sacred.
I am well aware that plenty of other myths and legends can and should be turned into nations. I just remember a bunch of people complaining on Steam about how Greek-orientated the recent nations were when Mekone was released and they are definitely going to start complaining again. That was meant to be a little joke, sorry.
All good, I ain't mad at you, only mildly annoyed at Illwinter's approach.