This build is aiming to keep you alive while doing great dmg in the maelstrom arena.

Race: Dunmer for fire damage boost. While having lower regen than altmer or breton, dunmer outperform the other two damagewise and can easily use vampirism, even in fire heavy rounds in vMA. I intentionally post a build without MA weapons because people who beat it dont need any build advice for it, even though you see a lot of builds around that include them for beating vMA, which is kinda stupid.

Gear:

5x Scathing Mage, Julianos or TBS (all except head and shoulders, haha, shampoo joke)
2x Valkyn Skoria (one medium, one heavy)
All divines, of course!

Julianos and TBS. The reason for scathing is that both elemental blockade and Refreshing path proc Skoria and Scathing mage, even though they are considered as DoTs. This is due to the description: it says that it does damage every second, not a certain amount over several seconds.

Force Pulse vs Swallow Soul:
in vMA, swallow soul is needed, so force pulse is only viable if you really know what you're doing. With scathing mage, use force pulse, because it has a three times bigger chance to proc it.

Jewelry and Weapons:

There are Several viable alternatives for jewelry and weapons here. You want all spell damage enchants on jewelry, as well as crusher and weapon damage enchant on staves. Weapons all sharpened, or precise with scathing mage.

Easy to get, though slightly less effective: Shadow Dancer or Vicious Death. Those two are easy to obtain and deliver solid results, as the 4 pieces give you Spell damage, spell crit and max magicka.
Better choice:
Infallible aether gives you minor slayeer, which is incredibly powerful, plus more spell damage and spell crit.

Moondancer gives you more max magicka and spell damage as well as minor slayer. No big difference in results, but when using scathing mage, more crit is helpful, so i would go with infallible, but i use it on two of my other chars and run out of jewelry :P

For group PvE, use two moondancer swords. The 5 Piece synergy is crazy powerful with scathing mage, and on your aoe bar, you dont need light or heavy attacks. Just make sure to get your healer to use orbs and you're good to go.