... or it's as useful as slapping a 8million HP ogre with a wet blanket. Here's a decent post that I thought explained it well:

"It isn't useless, but generally not worth it." (in nightmare mode) "You won't be able to tank things and have it keep you up, you will have to pull back now and again and let it slowly work its magic. Typically though, because of that, you're better off relying on a heal aura and using an app guardian. Heal aura is -5 du to defenses, app guardian is +300% damage to 5 defenses, equating to a far greater exchange in terms of keeping things up. This doesn't apply in some challenges of course, where the mobility is far more important (Christmas, Thanksgiving in particular). Of course the fairy can heal faster too, so there's that.

With the upcoming heal change though, it will be less in the fairy's favor as maintaining your hp as a huge hp squire/countess won't be quite so mana intensive as it is now, where an alternative is tempting."

Until they buff the healing of fairies in nightmare, there's no point in giving up a spot for guardians (even if it's nerfed to 3x now) for a fairy. And no, a hacked fairy healing for 100k doesn't count. I mean, is a myth version of the Zamira fairy even available legit? I seen one or two with 70^+ on people but they had retarded single digit or teens stats which makes me doubtful and I don't have warping core maps.

You wont be able to tank no, but if you have full resistances, and avoid kobolds then you wont loose as much HP, and can be quite suffient dps if played right. If you choose App / Huntress gaurd why not make a ranged dps. I don't see the point with the guardians for a Countress/Squire then. Eitherways for Mistymire NM survival 20+ you wont be able to do jack**** as squire anyways, better of with a ranged monk or huntress and that app / huntress guardian. But for challenges and easier survivals countress can be useful and fun, but the fairy can come to good use, even none hacked fairies can heal you a fair amount. Just kite ogres and avoid kobolds then it should keep you topped

I'll agree with you about fairies for anything but the toughest nightmare settings. It's probably the best/safest pet for meleers then. At least it's an excuse to use anything other than guardians. All I know is squires are a bit more resistant to Murphy's Law when the game lags the instant you decide to repair that frontline and I'll leave it at that.

With splash effects, spell effect flashes removed and graphics on low it shouldn't lag like ever, even if 20 fire ball towers shot right at ye

But ye in generel Squires/Countress's can survive a great load of damage