For adds you run a full debuff setup with Yolnahkriin, Thurvokun and whatever set is needed from Alkosh, Livewire and Frozen Watcher. The reason you use Yolnahkriin is because you usually taunt ranged adds and the Main Tank taunts melee adds to they use Dragon’s Defilement.
Typically you shouldn’t need 2x Alkosh but you could. Livewire will increase DPS in add phases as you’ll causes AoE concussion and Off Balance very reliably, make sure you use a Lightning Staff with Livewire. If your group needs AoE Minor Brittle then you could use Frozen Watcher with an Ice Staff to proc Chilled, Minor Brittle and Minor Maim.
Thurvokun could be used alongside the Main Tank using Lady Thorn so you can AoE Major and Minor Maim the adds, if you are using Frozen Watcher then you won’t need Thurvokun as they do the same thing.
Last Boss & Hardmode Gear
Pretty much any race is playable here. The common races are Nord for Resistances and Argonian or Imperial for sustaining.
The best Mundus Stone to use here is: The Atronach for the extra Magicka Recovery,
As standard we use the Bewitched Sugar Skulls which gives us Max Health, Magicka and Stamina plus more Health Recovery.
You can use regular Tri-Stat potions here.