Your main question is how you are going to handle
Piranas and
Nightmare as
Frozn folds to SOB (they can't hit for enough damage otherwise) and
Vortex is much less threatening as well.
The
Frozn that handle SOB:
Stompah: Staple, operates normally without bonus
Haaken: Staple, SOA is key against
Piranas and
Nightmare
Mikaal: Mandatory for
Frozn mono, run him if you are going 5/3
Tiwi Ld: Usually a staple but not so good here because you already have
Vortex for Defeat
Annuaqa: Inconsistent ability and conditional bonus makes a lousy character, her only redeeming feature is SOB against
Piranas and
Nightmare.
Tihmpah is better if you have 4-5 other characters that can handle SOB.
Frozn desperately need a character with SOB ability.
Elishka: 9/5 on courage is ok against SOB
The biggest problem is damage, as
Frozn have no character with more than 5 base damage. This makes
Frozn a lousy pairing with
Vortex.