Some Sorc OT: Boss - Zauberer Baue PvE - ESO

Assuming your MT is Winter's Embrace (MResolve for gorup) + Earthen Heart (Stagger & mBrut)

Make sure you don't have any skillpoints into ‘Tri Focus’ passive (1st passive in Destro Staff skillline)

Cruxweaver & Arc's shield are mainly to generate ulti, make sure you're consuming at least 1 Crux every 8 sec to abuse Impacable Outcome passive. You can instead use Siphoning skill every 4 sec, both give same ulti per sec outcome but Arc's one occupies less GCDs since it has 8 sec cd (and since last update all ultigen cds are shared so you can't abuse both at same time). To generate crux with cruxweaver just make sure to step into some AoE (every 5 sec taking dmg with Cruxweaver active will give you crux).

Arc's shield is purely for regen passives, Barrier may be better tho if you're blocking a lot.

If other tank has Winter's Revenge for trashpacks Pulsar is kinda wasted slot and Trample with Hero is gonna be way better.

For bossfights when you have some time when you're doing nothing make sure you have all buffs and debuffs running (Ele sus, Colorless, Wall of ele, if it's mitigation-heavy fight chains with MMaim as well, Hero Trample) and just spam Ele sus (with Baron it gives 4 ulti per cast).
Also for Trample recast it when timer is on 4, bc it has 1.5 sec cast time and timer gives you time for speedbuff what lasts 2 sec longer than MHero and you're mainly using it for MHero.

For sets overall I threw some basic OT setup but mainly:
 - Make sure Sax or PP are on bar you have ulti you'll be using
 - If you have 2 proc sets (like Sax+PA) if you go one set on one bar, other on other bar you'll be able to slot 1piece Trainee for 1.5k health and mythic, for trash Ring Of Wild Hunt is op and for bossfights Velothi is just free dmg you can have, tho also Death Dealer's Fete is free basic stats if having more health won't hurt you (in DoT based fights you wanna have lower health).
 - If you have at least one nonprocable set (like PW or LE) you gotta have it active on both bars, if you have both sets that just have consistent effect you gotta slot one on body and other on bars having both bars from one of those sets. If you have only one sec like that and other procable (like LE+EC or PW+PA) you can slot nonprocable set on body and procable frontbar and go for MA Ice Staff backbar for more dmg