So I was doing One Small Favour, and going along fine (apart from having a hard time finding a white-robed, white-caped Seer in a bunch of white buildings), until I got the scroll from Cromperty. I wasn't expecting a big fight at that stage, so I ran off to get food and armor and the like. Coming back, using the Incredible Reflexes prayer (though not, I think, Ultimate Strength; I forget why) I was hitting occasional twos. I got the Slagilith down to a bit over a quarter health when it suddenly lost interest and turned inanimate.

 

My question, therefore, is how do I do more damage more quickly? Please don't say "grind strength"; I hate grinding. For the record, I have 55 in each melee stat, 48 prayer, 55 magic, 51 ranged, and 39 summoning, and am using Excalibur as my primary weapon.

1) Get a better weapon

2) Get better stats

 

Thats pretty much all the advice I can give; if you can't do damage fast enough as you are you need to train and be better.

I've heard of people with mid 70 combat stats having some trouble downing that guy before he loses interest, so yeah 55 prob aint gonna cut it.

try using a pickaxe.

I'd say try going for a crush weapon maybe.

 

I didn't have much trouble with him unarmed at 50 combat.

buy super strenght and super attack and maybe super def

I've now tried again, and succeeded, without any of the strategies suggested here. I put on splitbark armor, an ammy of magic, Karamja Gloves 1, Falador Shield 1, Ardougne Cloak 1, and beacon ring, turned on Protect from Melee and Mystic Might, and spammed Wind Blast. The damage per hit wasn't much more than with Excalibur, but it was far more frequent, and I only used two prayer-potion doses.

I've now tried again, and succeeded, without any of the strategies suggested here. I put on splitbark armor, an ammy of magic, Karamja Gloves 1, Falador Shield 1, Ardougne Cloak 1, and beacon ring, turned on Protect from Melee and Mystic Might, and spammed Wind Blast. The damage per hit wasn't much more than with Excalibur, but it was far more frequent, and I only used two prayer-potion doses.

 

I was going to suggest magic. For many lower levels, magic is usually the fastest option, although perhaps the most risky.