Frozn need pretty much everything...
2★ are simply not what they should be for the clan, Windzy was the first character to be built in the right way, but still not what Frozn needs. -3 damage min. 2! easy as that
3★ are either very unstable (Sah Brinak) or not really competetive like Annuqa. Haken is pretty good though
4★ most are unstable as well, what is really really bad for a 4★ card. Only Stompah is good, very good. But you need more than one good 4★ most of the time
5★ Slowly grow to pretty nice T2 fighters (Brok, Rad, Ayah and Thorpah pack a punch together, Kalindra outside of DM too), but a really good ELO card is still missing. All can be used for ELO but none of them really is worth the 5★ in an ELO deck (besides Kalindra... ha...ha...)
The clan needs some damage nuke, atk mani and a character with "stop:" as well as protection Power+Damage to keep them stable in some way.
I'm sorry, but I've come to the conclusion that Frozn cannot be saved with new releases. Their bonus makes them too predictable. You are ALWAYS going to want to play your strongest cards in Revenge, which makes your strategy completely transparent compared to other clans. Having to plan your play around 1 good Revenge card in your hand is challenging enough, but also tends to carry a great reward. However any time you half-deck Frozn you risk drawing 3!!! Revenge cards and one bonusless card. Even worse, if you play Mono Frozen, you have to regard your strategy in terms of making the most out of 2 Revenge turns. That means a single SoB, SoA, DR or Defeat card -- anything that mitigates without having to win a round -- can throw your strategy off completely.
Here's what IMO CAN save the Frozn clan.
Throw a big, story-based event, where the Frozn come to a tentative truth with the citizens of Clint City, and build a miniature version of Glatz somewhere in town, or something of that sort. Do some kind of competition. Award prizes. All leading up to...
The changing of the Frozn bonus!
Give Frozn cards +1 power or +1 base damage, depending on their individual need. Then reduce Frozn bonus to Revenge: +1 Power and Damage. This way Frozn are 1 stat point higher out of Revenge than they were before, but 1 point lower in Revenge than they were before. Some tweaking may have to happen, but the clan would quickly become ELO-playable from there.
If the Frozn are really as unsaveable as you make 'em sound just because of their bonus, Ghelas, UR should just pull a Fantasy Rivals and create some Frozn cards with a different bonus(courage: +2 power & damage for example). Far less drastic then completely changing the way a whole clan plays.
They are pretty usable, if you ask me. They are harder to control than the other clans, but they do have some good cards that are usable on non-revenge turns. The problem with cards like Bankee is that they're great on confidence turns but really bad against SOA... If Bankee was a 8/4 confidence +3 life, he'd be great in my opinion.
@ghelas that's due to your own play style. Frozn are able to be played without their bonus. Cards like Thorpah Stompah Rad and Tsuka Brok Ayah Mikaal even Kalindra don't need to rely on their bonus, they have solid stats and or abilities that can help you win without the need of their bonus. Rad and Brok are two great recent additions to the clan, both have solid base damage and abilities that allows you to 2HKO on a non revenge turn.
But I do kind of agree with you, UR needs to start giving Frozn more cards that are not reliant on their bonus, i.e. cards that already have solid base stats. A 5* 8/6 or a 2* 8/2 , even a 4* 7/5. Frozn needs more cards that allow them to win on a non-revenge turn.