If youre playing sorc first then the answer is simple.
Also when using frenzy, make sure that your offhand weapon is not shorter than your main hand.
Otherwise you will whiff half your swings.
Doubleswing normal mode
Malice flail and taltaltal flail
Just do 1 pt weapon mastery
Frenzy nightmare mode (since you said frenzy lol)
Black is garbage because knockback. You can use it but its up to you.
For axes
Dual butchers pupils if your sorc finds them
Honor naga
Coldkill hatchet
Any combination of these if you go swords
bloodletters
headstrikers
Spineripper
Heartcarver
Honor whatever is easiest exceptional sword, great sword? Dont remember.
To continue mace
Honor knout
Pretty much all the one handed exceptional maces are good
Fetid sprinkler
Zakarums habd
Frenzy hell
Until they remove %target flee from lacerator, lawbringer will basically always be the superior option for frenzy pvm.
Lawbringer phaseblade on offhand. Dirt cheap and amazing for safety and damage support. Sanctuary aura 660% ed to undead which is a third of all monsters in game, fhr stun knockbacks undeads which are most of the games actual threats (gloams stygians oblivion knights rot walkers etc), garbage damage but casts decrepify 25% of the time. Since most things have 50% physical resist its basically doubling the damage of your primary, plus 660 ED to undeads.
Mainhand
Fleshripper fanged knife - decent damage, excellent mods
Ghostflame legend spike - ignores defense, mana leech, good damage not much else
Lightsabre phaseblade - dirt cheap, fast, ignores target def
Crescent moon - phaseblade works but you could probably go mythical sword for the damage
Headstriker, preferably upped - slow but good damage, cheapish
Oath eth conquest sword - best pregrief. Pray for high roll, that low end 210 ED hurts bad
Then grief pb
Unbending will can only be made in phaseblades and colossus swords/blades.
What ruins it is chance to cast taunt, which overrides decrep, which basically cuts your damage in half.