So a while ago I drafted up a four player team concept of Devastation builds. I wanted each build to support the team for higher SR, while also bringing an extra Devastation to the table. As a team in higher SR (90+), it ultimately fell apart, because the tank didn’t have enough aggro holding capabilities; the other DPS would take aggro and die. However, as individual builds, they’re a lot of fun so I thought I’d share 'em. 
Tank: Phys damage, golden devastation: https://www.grimtools.com/calc/bVAXaD62
This build is tanky enough to finish Gladiator Crucible 170 with no buffs/banners. It’s a little slow, but it gets there 
Vitality DPS: Red Devastation with double projectiles: https://www.grimtools.com/calc/8NKwGqQN
This build actually is my favourite - it is the most balanced between survivability and offense. The damage output is significant. It also has 5 Reaped Spirits floating around to distract enemies for you, reduces enemy damage, has good damage absorption options and Mirror + Mark of Torment.
Elemental DPS: Pink Devastation with runes: https://www.grimtools.com/calc/DV9EORQV
This build was intended to bring inquisitor seals to support the tank, and also bring as much elemental damage from multiple sources as possible. The screen lights up pink with your inquisitor seals, pink devsastation and Arcane Currents, with whirlpools, Elemental Seekers, Fissures and Chain Lightning flying out of you. This build feels like a high damage and very pink, elemental mage.
Healer concept: Two Wendigo Totems + Vitality Devastation - https://www.grimtools.com/calc/gZwaoWk2
I never played this one, but the intention was to bring 2x wendigo totems to the team plus vitality damage devastation. I think it would do well in teams, but would lack damage to be significantly powerful as a solo character, despite the obvious healing support that it provides.
Glass Cannon: Flame Devastation + Mortars + Apocalypse - https://www.grimtools.com/calc/m239OBqZ
This one we didn’t use because of it’s very low HP, but I wanted to throw it in there to continue part of the rainbow Very high AOE damage output, but fairly low survivability. Especially in higher SR!! Also steals aggro constantly, which is not a good pairing for it’s low HP. 
Other devastation builds were considered - Aether damage and Cold damage, but the ones above were the most interesting, fun or effective that I could come up with at that time.
Enjoy!