spirithost, easy to book has 50% attack buff, speed aura

SPIRITHOST SKILLS

Reap [ATK]
Attacks 1 enemy. Heals by 50% of the damage inflicted.
Level: 2 Damage +5%
Level: 3 Damage +5%
Level: 4 Damage +5%
Level: 5 Damage +10%
Damage Multiplier: 3.7 ATK

Strengthen (Cooldown: 4 turns)
Places a 50% [Increase ATK] buff on all allies for 2 turns.
Level: 2 Cooldown -1

Dark Gift (Cooldown: 6 turns)
Removes all debuffs on all allies. Places a [Block Debuffs] buff on all allies for 1 turn.
Level: 2 Cooldown -1

Aura
Increases Ally SPD in all Battles by 10%. 

hexweaver decent, not fam w/abyssal

I don't think you should pay any attention to the class of the champion. Don't treat this game as a typical RPG. Just because they're classified as support, doesn't mean you need to treat them as such, nor should you feel the need to necessarily have a support on your team.

With that being said, Spirithost is the clear best of those options. As to whether she's worth actually leveling, that depends entirely on your team, but my expectation is - no, don't level her at all, or at very least don't waste time going beyond level 50.

None-  wait  for  a  better  champion.

Ironhide? Hexia? Thenasil? 

Of that set, Ironhide would probably be the most useful, but - again, wouldn't bother with any of them. Save your food for more useful champs.

Ironhide  is  good  for  Faction  Wars-  but  I  would  still  wait  on  him  until  you're  working  on  that  more.

Hexia  can  hit  hard  when  paired  with  Gurptuk,  but  that  requires  lots  of  good  gear,  and,  of  course,  Gurptuk.

The  only  one  that  I  would  build  is  Thenasil.  He  is  an  A-Tier  Support  and  is  very  annoying  in  Arena.  Build  him  with  high  HP,  DEF,  SPD,  ACC,  and  RES.

basically everthing except the offensive side of the game lol

What is best antifact for the champions? 

Abyssal is decent/good (depending on your rooster) for Demonspawn Faction Wars but for general play I wouldnt upgrade any of them

he wont do any damage, so fast and tanky (lots of HP)

if you can include Accuracy for his A1 but it comes after Speed/HP/Def