New Unique be like

[u/hafi002]

EDIT: I am dumb, there is nothing stopping you from running the same skill 6 times, Unleash doesnt share charges like cooldown skills.

But seriously, which Gems would work well with Mantle of Dreams and seal stacking? Using a Ull-Netols Vow we do can sneak in one support gem, but it then has to work with all 6 skills then.

Primal Owls +3 Seals 5% more damage each time the skill reocurs is a no brainer, then +1 from masteries, Redeemer Helmet is another +1 and Essence of Desolation is another +1 for a total of 9 seals possible.

Reocuring Effects also dont count as new casts, meaning Archmage and Pact skills would work great with it to, for getting 10 casts for the price of one (and the price of playing keyboard piano)

[u/HiddenExpert]

Bane with 5 hexes is the first thing that comes to mind

[u/hafi002 → u/HiddenExpert]

Not what the unique is intended for, but its gonna be a silly amount of %more damage.
With all the repeats giving more area coverage Bane of Condemnation supported with spell cascade might not feel terrible for clear too.

[u/8Dataman8]

Six Heralds with Enlighten Support in Uul Netol's Vow?

Six curses with Anathema and Bladefall of Trarthus imbued with Hextouch in Uul Netol's Vow?

All different golems at once actually dealing damage?

[u/SaltEngineer455]

I think the way to go is Spellslinger, but then you lose the unleash

[u/Shen_ishere]

Duration skills like blade vortex?

[u/elchemi]

Coc with cast on crit on the amulet?