I was using my Thrower to fight these, usually taking about 6-8 mins and a bunch of bandaids. My template is approximately this (finishing off the last points in bush and tact still):
120 Throwing
120 Tactics
120 Bushido
100 Anat
90 Heal
40 Necro
60 Spirit
70 Chiv
My weapon is a soul glaive imbued with demon slayer, 30 SSI, 30-something Mana Leech, 30-something Stamina Leech, and however much Damage Increase fits after that. My suit, in addition to being all 70s, has the following mods: STR 26, DEX 26, INT 16, HPI 32, SI 31, MI 14, SSI 50, LMC 37, HLD 30, HCI 35, DCI 15, DI 85, HPR 2, SR 2 (although the DI might be a little different from when I imbued the first and last weapons).
Basically, all I do is find one of the minions that are on that island right next to the starting island and lure it towards the gate area. Then, standing as far back as possible, in wraith form, I just continuously throw at it, casting EoO a couple times during the fight and using bandaids whenever necessary. When I am hit, I take about 60 damage and lose almost half of my stamina, but the bandaid gives me back more than enough hits and the weapon usually restores my stamina in full within 1-3 throws, so I rarely have to cast Divine Fury. I also continuously cast AI whenever I have enough mana, or else lightning strike when I don't, and in the event that I had to teleport onto the island to lure a creature (I carry teleport and protection scrolls), I also will honor it if possible (can't honor it from the ground when it's on the island though). This keeps it from being able to walk over to me and if a friend joins me, we can usually take one down in under 3 mins, with one of us x-healing the other, as only one char seems to take any damage - i've heard its possible to have a range on the throwing weapons longer than the minions range, but I am not sure how this is acheived, although when I redo my suits again, I will get more of some of the stats added as well).
Using this method, I have completed the quest once and have about 15 extra books for trying to get a second (have 8 of 10). And it actually seems like my method could have easily been scripted, at least the part where it actually fights the minion, but sadly I didn't feel like spending the time trying to write the code (instead working on several other projects I have in the works, none of which are on topic for this thread!).
I will have to try the ice slayer talisman though, as I hadn't tried loring the minions, so if i can do even more than the 200+ damage I am already doing, these things might die much, much faster!!!
to give a poster a reputation bump!