Phenexa and Ray, 10000%
Which is first is gonna depend on your other roster needs. If you lack support heroes, or wanna improve titans, then Phenexa
If you lack dispel and/or have another VF/F fire offensive to pair with Ray, then Ray
But honestly, you can’t go wrong with either. I’d personally opt for Phenexa first, as healers are always needed + that bard bonus is amazing 
. but the new Magic passive is quite insane - esp if you have another magic hero to pair with your Ray - so yeah, def no wrong answer
As for the rest of your options, the only ones I’d consider, but much later on …
Asterius
Awesome for his stackable DD, he’s a great pair to just about any hit-3, especially in fire. Also makes him a great addition vs titans. A bit more versatile than the latter [here], he’d be who’d I’d max third
Zenobia
Her utility is 100% specific vs green titans / mythic titans. But there, she has absolutely no competition. Although, she doesn’t need mats to be able to perform for you, if she does get em, your scores will only improve more
Emilio
Unfortunately doesn’t benefit from Ray’s EDD, but Ray’s DoT will precede Emilio’s SS very nicely, ensuring you always get the heal. Probably providing just enough to hold you over, to get Ray to his second charge, after. Although, with Phenexa, I can’t imagine these two will be your first choice for support. But for things like war and W3K, you’ll still need the depth
The Others…
As for Isrod, Octros and Skargremar, they may be worth it down the road, but comparatively, they seem to offer too little [in comparison]. Isrod could be great for the mana he can give - esp if you lack that skill elsewhere. Octros can still be serviceable defensively, and help survivability offensively. And Skargremar offers a bit of mana control and blind - two amazing supportive qualities - in one, so def potential there too.
But yeah, to me, the [first] choices are obvious, here. But as always: go with your gut. If it’s telling you something different than me, well then, to hell with my advice. It’s your game.
