You're ignoring 50% of what I wrote by focusing purely on petrificiation/disintegration--it's just as easy to get torn to shreds by a horde of monsters (remember, it only takes two melee hits to kill someone at zero HP) or grappled and pulled out of healing range of the healer or drained to zero HP by Shadows.
Never my intention. Just picked the 1st 2 effects that can ignore this ability and added an etc.
If your DM wants to kill a downed character is indeed pretty easy.
But in most tables I known is kind of an unwritten rule that downed characters would be ignored while active enemies still exist. But that's very unrealistic so let's ignore it.
Even ignoring that, is normal to expect that many enemies would stop attacking the 1st time that the character fall. But as soon as it fall once or twice and comes back up, they would certainly do something more permanent.
It will be pretty hard to grapple someone within 30 feet of the Guardian if you're not flying.
First of all the other melee members of your party are very likely to have High Dex or Str values, and is pretty common for then to also have proficiency in Athletics or Acrobatics, so it will be hard to grapple then. Also, is much rarer for monsters to have skill proficiency than PCs.
That's irrelevant if they are down but even so, the monster will be carrying someone, resulting in half movement, and it is through difficult terrain area, movement is halved again. So, a 30 feet moving enemy would carry ally outstanding 7,5 feet away from you. 15 feet if they dash. Even a tree can follow that.
Flying or very high move speeds can avoid that. I also think there is a rule somewhere that let you move while grappling someone without spending extra movement if you are at least 2 sizes bigger than the target, but I am not sure. So, Huge or Gargantuan enemies can also move away grappling easily.
Another thing that makes harder for the enemies to move away are the ranger spells. Just entangle, spike growth and ensnaring strike already make much more difficult to move away from the Ranger. Probably, there are also other spells that also work for that purpose.
And even if they actually grapple an ally out of your heal zone, the one attack they lost to use grapple is likely to deal much more damage than you can heal in one or two rounds, so that is good.
The aura is useful only when someone is below half HP, within 30' of the Guardian, the Guardian has already transformed, and the Guardian is not incapacitated. It's not bad, but I have yet to see someone point out a niche where it is important. All it does is make easy fights easier and slightly cheaper. Of all the deaths that I have seen since starting 5E, maybe 20% of them would have been prevented by having a 15th level Guardian around.
I am not really much worried about the combat potential of the ability. Other than reviving fallen characters is mostly fine. What I do not like is the infinite out of combat healing.
That ship has sailed already. You can already heal thousands of HP per long rest by PHB rules by 10th level. Plus all the extra HP that is available via Polymorph, wildshaping, and temp HP sources (warlocks, death monks, battleragers, etc.).
Most of that only works by spending resources or with some pre-requisite.
A bard or a paladin can indeed use Aura of Vitality to heal everyone to full, but the paladin is using his highest spell slot available, and the Bard one of his precious Magical Secrets and one of his 3 3rd level slot that they have by that level. I am not saying is a bad use of a spell slot, it is an outstanding one, but it has a cost.
And while in theory it can heal thousands HP, it will probably heal a two or three hundred at most.
Edit: I made this last statement thinking Aura of Vitality lasted 10 minutes. Ignore it.
Polymorph limits highly the capabilities of the targeted PC. If it was played correctly instead of generating a tactics master 3 intelligence T-rex, it would be a much weaker spell, but that is another discussion. And again, has a spell slot cost.
And what battlerager ability are you referring to? The one that gives you up to 5 HP by giving everyone advantage to hit you? How is that even comparable?
The monk and the warlock abilities are indeed pretty good, but TempHP still don’t stack and the power of the abilities will vary wildly by the presence or absence of mooks on the battle.
As I read it, the Guardian's ability works only for the rest of the party, not for the Guardian. It's kind of the inverse of the Champion's ability in that regard.
I missed that on my 1st reading.
“I am obviously my on ally so it should work on me” Said a player somewhere.
Edited to organize and add stuff.
