Yes
You just have to make fresh map

To also confirm yes it considers the quest "failed" this was a change to prevent people from spamming the quest NMNM to fight a lot of eps very quickly. I think after a few days you can re-attempt it.
Basically you can fail any mob quest by just opening and closing a group or logging off

That I did not know, very interesting to know!

I always kill sneaky on my own and it generally only takes a couple minutes (2-5) regardless of the melee char I'm playing. This does require some preparations though, but it's super easy to do once you know what to do and get the right stuff for it. This is extremely budget friendly as well

1. Make sure you spawn sneaky as soon as possible; lvl 20-30 is the ideal spot and the earliest you can spawn him while soloing. Spawning him at 40+ is not recommended if you plan on soloing him as the mana cost per cast, and your mana pool becomes a massive issue.

2. Use "garbage" off-cast gear with tons of mana with a tiny bit of int. This is far better than pure int or high int with some mana. Some examples of what I use, these are generally very cheap to buy and helps way more than any expensive stuff you can find.



3. Start glyphing and use mana/int glyphs, no need to go for quality glyphs, something like this is perfectly fine.

Angelic glyph III
Use Item to Receive Effect
Effect Duration: 27 minutes

+80% Enhanced Effect
+7 Intelligence
+254 Max Mana
+1 Mana Regen
+1 to 2 Life per Attack
+1% Power Shot

4. Start filling your vault with high quality shrines early on e.g. angelic+ T3 items. These fill most of your mana pool early on and then use the next step to max it out again before heading back into combat.

5. Use terrible mana fish and lots of them I usually just buy stacks of a couple hundred 100-250 mana fishes for anywhere between 1-20 fg on the market. Stuff like this is top tier for this purpose, don't bother cooking them, just spam mad quantity!

Rare cod fish
Use Item to Receive Effect

Heals 187 Life
Recovers 174 Mana
Quantity: 270

Remember that when you solo and want to kill IT with off-caster Gear, IT Takes Up vault-slots.

How so? Keep your sneaky killing gear on a mule if you’re too stingy to sacrifice 5-15 vault slots at all times. Pick it up once you’ve met the prerequisites for sneaky and send it back once he’s dead?

You lose the quest when you leave now remember

You don't need to leave since you're going to pick up your gear before you even attempt to spawn him in other words, you only pick up the items that you need at the levels in which you try to spawn him and then return them to the mule once he's dead

Good Point.

My Statement ist basd in pure solo and trying to fully Explorer all the time.
Maybe i shouldbreconsider my strategy and add some caster stuff