For COF, you probably want to get Xanos from the arena instead of Ethera. Ethera does not really shine until awakened (level 90+) whereas Xanos shines at all levels.
Firehawk - good choice, keep working on him
Mariana - drop for Jasmine eventually
-some might argue that LingLing and the Li Twins are better than Jasmine but their SoulStones are much harder to get
Blood spear - Good for HoL (level 65+) and Raids (need access to chapter 7+ in Campaign), not really useful in anywhere else.
Taurus - Similar to Xanos, good in CoF, Raids (except boss stage), Campaign, Arena, only bad in HoL.
Malrath - His SoulStones are pretty hard to get (VIP 11+) but he is a good DPS tank. Unless you can get his SS, I would drop him since he'll be stuck at 3*
Zem - Arguably best hero in the game, that excels in pretty much every aspect of the game. He should be your #1 priority in the CoF store, get him to 6* then work on Taurus is what I would recommend.
Flora - drop for Jasmine, but you can use Flora until then
Vincent - He's good until P+1 which is around level ~60, then you should drop him (since you'll have Zem + Xanos)
Elric - A tank with low damage but easy to access SS. You could use him in on of your Epic Arena team (you'll need 15 heros) and having a tank there is not so bad.
Ember - drop immediately
Drago - Just use Elric if you want a tank, Elric have a awaking so yeah..
Garrick - He is really good, you'll want to work on him ASAP. His SS is not available until level 60, so he'll be stuck at 2* for some time. Garrick one of the best single target damage dealer in the game. Great in PVE, decent in PVP with the right set up, or right opponents. He is a great counter to Xanos in the arena, assuming AOE doesn't kill Garrick right away.
Octo - SS in bad place (same as Zem + Taurus) so consider dropping
Alana - a different version of Bloodspear, but easier access SS.
Kong - same as Octo, Kong is pretty good in my opinion but he's still really new.
Tashi - too new for me to judge
Osiris - Limited usage, and outclassed by other mages
Arachna - Good counter for physical heros, and easy to access SS. Good hero for epic arena, but that's about it.
Ezio - same as Malrath, unless your can afford 7*, don't bother with him.
Gale - easy access SS, but does not excel in any areas. Good hero, just not great.
Leon - same as Drago
Ulfang - outclass by other hero with similar kit.
Last edited by FakeLikeFaker
on Fri Jan 06, 2017 8:56 am, edited 1 time in total.