Glyph for radials is kkvk8gsj (layer 3)
Most weapons will require 2 cold abyssals and one elemental (fire, bolt or arcane) gem... which can either be triangle or waning (your choice - I generally find waning easier to farm for as you know what you're getting and don't have to farm the watchers until you happen to get lucky).
Radial, Radial, Waning is usually my preference (this is the base version of the saw cleaver and spear -- a great choice for a fire weapon because of the serration dmg to beasts which is already built in). It's possible to choose the lost variant (radial, triangle, waning) and get a little more AR (as fire and bolt can be a second stat on those gem shapes), but I'll explain why I do not do this, and prefer 2 radials:
My fire saw spear setup:
Radial 1: +65 arcane scaling (abyssal), atk vs open foes +5.4%
Radial 2: +65 arcane scaling (abyssal), atk vs open foes +5.8%
Waning: Fire atk up 24.8% (abyssal), add fire +14.5
Build it how you want -- But those 2x open foes bonuses are really handy and result in a good deal of extra damage a lot more times than you think.
Anyway -- to the Elder!
Phase 1: Farm him with a heavy "stunning" weapon. Lets you get more hits off each time you attack.
Note in the video - I wait for him to fire an arrow at me THEN attack. You've got a couple seconds whenever he does this where he will not attack again. With a weapon like the wheel I am getting a shit-ton of dmg off each time too.
Phase 2 --- blacksky eye. It stunlocks him. He can't do anything to you as long as you've got bullets and keep firing until he is dead. With 50 arcane that's 30 bullets (25+5).
Good luck!
![](https://i.ytimg.com/vi/hWHd5JeDkpY/maxresdefault.jpg)