https://forums.elderscrollsonline.com/en/discussion/300935/qam-magic-dw-sorc-1vx-one-tamriel/p1
Check out this thread for builds.
Seducer is out this patch.
Try some of the new sets, like spinner and infernal guardian and see if you like them. Try the new witch's brew food. Come up with something that works for you.
Willpower and engine guardian are still excellent and widely used.
Here's another great build from Hexys:
https://forums.elderscrollsonline.com/en/discussion/297514/hexys-magicka-sorcerer-pvp-build-for-update-12-one-tamriel-2-6-5-duels-and-small-scale-pvp/p1
Hope that gives you some idea of what you want. Once you have a picture, have fun with the set farming.
I was think of going 5 spinners, 2 Grothdarr, 3 willpower and maelstrom destro and jump in groups with proxy Det, impulse spam, Grothdarr and eye of the storm going and just melt everything but I don't know if that's effective enough haha.