Generally, ancient grove is much more easy with ranged characters (mage or gunner) than a melee character
There is 3 main difficulties: deathstalker manticore (aka kitten) - you can’t lifesteal from it, + he got a RR
Gargabol - main attack with savagery mechanics (with charges, becomes more and more damaging with every hits), big amount of resist reduction, and (main trouble) a fissure, that could annihilates you in seconds.
Slatssar - just run Jokes aside it’s a real pain for melee character (fumble, RR, reduction of health, reduction of DA)
Just friendly warning, Gargabol is more deadly than Lokarr.
1st phase Gargabol is pose little threat if you equipped with decent gear. However, pay attention at 2nd phase of Gargabol. When that thing bow down, he will spawn 2 fissures which can one shot even most durable builds. Also make sure to overcap your chaos and fire resistance.
What you can do with Slathsar (or whatever that thing’s called) the basilisk is use the pillars in the room as cover. If you play a build that doesn’t need to be in melee range you can block the direct shots and only have to stand in the poison pool. Sure you get a massive fumble debuff but who cares we’re casting spells and killing it (sort of) safely.
For melee builds, I don’t know, the whole dungeon seems designed to crush them. I did it once, now always use something caster or ranged…
Never had any problem with two Melee characters here - an electrocute warder and a DW Aether Death Knight. With enough DA most is facetankable but look out for Gargabol 2nd fase (fissure). That got my DW character once or twice if I wasn’t paying attention. The heath disappears fast.
And don’t do most of the end bosses in GD if your resitances aren’t capped - but that should go without saying.
Had an Octavius Forcewave Tactician that breezed through it. Basically ran around Forcewaving, Garb and the bask guy weren’t a problem really, just took a bit of time. Could probably have faced Garb a little more, but I played it safe.
The Deathstalker dude was rough, really had to stay on my toes. I think at one point he knocked me down to like 100hp (A little under 15k max) in one of his blink attacks. Dudes no joke.
I ran this yesterday on Ultimate, the Manticore was no problem at all, I guess my physical resistance was just fine.
Slathsarr is tricky as Melee, his bolts would drop me to less than 50% if one would connect, so using the pillars as covers is key. You can zig zag around it, and when he cast his big nova you move in, do some damage, and you move back for cover.
Gargabol totally took a dump on my with his Obsidian Anomaly (the fissures) even with over capped fire resistance and a Flamedrinker Ointment .