@Natural-Lite here you go. My opinions of all heroes right now… keep in mind that I’ve only been playing with them for a bit less than a week.
Nordri
Great addition to the 3* roster, with him and Gunnar’s costume though we’re going to see a heavy shift in CE Rare events to blue. I wouldn’t be surprised to see Gunnar (costumed), Nordri, and Gato x3 for all top teams in all but Avalon.
He’s basically a straight upgrade to Karil too for both CE and raid tournaments. I’ll be pulling all my barbarian emblems from him to give to Nordri.
Ei-Dunn
She’s an upgrade to Chochin, better speed, better mana delay duration and (mostly) better stats. Did anyone really ask for a Chochin upgrade though?? 
Well she’s a top 3* hero. Despite paladin class though she’s not better than the currently best red tank Bauchan in the rarity, but she will still make a very solid flank and wing, and a great offense hero too. Also worth noting that she’s better than Jahangir for spreading damage in challenge events, which is something that IMO has been quite needed for a while.
Mist
This is one of the best 4*s ever introduced. -64% mana delay to 3 on fast is lulz, she’s basically a yellow version of Proteus since that delay can ensure that skills charge at a snails pace. For me that’s the best part of the skill. The -34% special skill defense debuff is great too. It’s not as good as Jackal’s or a general defense debuff, but it does stack with all those! 
Mist → Joon in that order is completely devastating.
The buff block is more situational than anything but still nice. Will probably matter more on raid tournament defense – you can’t overwrite her debuffs with a buff, so she essentially forces a cleanse. She is fairly squishy as well, which is what keeps her in check from being too good.
Brynhild
She’s just okay tbh. Will make a good impact in raid tournament defenses, but other than that, she’s just a decent support hero. Green really didn’t need more of those, but she works well at that.
Fast healing and mana buff are nice even if they’re just to nearby allies. Can see her as a good tank with these combinations of skills. The dispel shield is also quite nice as it gives her a good matchup against Melendor and Sabina. However it is worth noting that you can still overwrite her mana speed buff with a mana delay ailment, such as Little John or Mist (she overwrites her Special Skill defense up too, with her SS defense down).
Mireweave
Very underwhelming hero, frankly she needs a buff in some form. 150% damage from 650 attack is pretty low damage, even considering v. fast speed. The +5% buff per use is too small even if it’s permanent.
I’m not really that excited about Mireweave – she does look cool at least.
Sif
Most players in beta agree that Sif is a pretty strong yellow tank hero right now, potentially a good replacement for those who want something more fresh than Guinevere. Counter damage is not affected by the damage reduction, and she buffs her center to charge their skills faster like Boss Wolf.
However, unlike Boss Wolf, a dispeller can completely wipe all her effects, and there are plenty of those in purple to threaten her (unlike yellow, who only has Vivica costumed). Worth noting too that pierce can bypass both her damage reduction and counter.
So she’s strong but balanced.
Freya
Opinions are mixed on her, some think she’s useless while others think she’s fine. Personally I think the fact that she’s a fast minion summoner is what is keeping me from suggesting further buffs to her. That’s really the golden aspect of her skill.
Minion healing is useless though. The minion attack buff is also situational, at best she makes a good partner to Puss in Boots on defense, as on offense the damage from minions is still kinda meh.
Fenrir
I just have this to say: This hero is insane!
Weak hit on full health targets does restrict his kill power and self-heal to be useful only later in the match. But aside that, everything else about this hero is crazy good. The mana bonus from killing a target basically makes Fenrir a v. fast hero after using his skill once – i.e. after killing one target, he can charge in 6 tiles again! He’s seriously so good, will be the best blue sniper released like this.
Norns
Twist of fate is very interesting, it essentially turns the resistance of the targets to a 2nd weakness which is pretty cool. It’s a lot like G. Chameleon’s color change – however unlike that it only affects the defensive resistances, and not offensive damage. This means it’s pretty useless on defense, since your tile damage remains unaffected – unlike G. Chameleon who forces you to use different color tiles (though that can sometimes work in your favor too) – and also the slash attacks and skills deal neutral damage anyways (only a few skills and minion damage benefit on defense, basically).
Still a very good hero though, people will be happy to pull.
Alfrike
Alfrike is the strongest hero of the bunch right now – even more devastating than Fenrir – and she may even be too strong according to some testers.
Everyone agrees her skill is super punishing due to mindless attack on the targets hit + health reduction. But not everyone agrees on whether she’s too strong or not, this being due to her v. slow speed.
In my personal experience, you absolutely can’t let her use her skill, and since she’s so slow she can be mana controlled far more easily than other purple tanks.
But that doesn’t mean that she’s okay as is either… jury is out on this one and I really need more experience raiding her to make informed feedback for her. I do think she’s amazing right now, but I’m just not sure if she’s “OP” given that she has trouble charging her skill too.
At the very least, the discussion so far on her is very interesting, and one thing I do agree with is having more counterplay in the form of health boosts available. That’d make the meta that is shaping up with S3 more varied and maybe players wouldn’t feel like they have limited options to fight her even if released as is.