Celtic Heroes

using askolds axe:
7400 delay
200 damage

rupture
double attack
giant swing
shatter
protective stance

giant swing doesn't hit much above my auto and has long delay, would pummel be better?

Tbh I wouldn't use any of those weapons besides ymir axe spear or hammer. The way to make a successful build using super slow strong weapons is use skills not based on weapon speed that deal weapon damage. You should also be nearly full str to get the most of the huge amount of physical damage these weapons. Here's my ymir spear build.

Shatter- Maxed
Double attack- up to level 205
Pummel- Maxed
Giant swing- Maxed
Skewer- level one
Frenzy- maxed

I suggest you use no skill gear except frenzy/pummel items. Go full daamage rings either hrungnir or aggy. I've been able to achiever 3.3k dmg with this build(probably could get 3.6k if I train spear ability). I've seen numbers even higher but even with such big numbers it is still extremely slow and I do not suggest using this build for anything except large skill hits unless your gear complements this sort of build.