Guild Wars 2

me and my friend are going to start play again and he wants to play a warrior. we plan on play wvw at max level and we were wondering what class will go good with him being a warrior. should i go for damage like a mesmer or ele. Or go tanky like him with a guardian. All tips and guidance would be greatly appreciated!

Uhm, play the class that appeals to you the most, then figure out builds that synergize well.

Why should your choice revolve around his warrior btw?

Good engineer

it doesnt revolve around his warrior, its just we played before and i had a mesmer and im not quite sure if i liked it, so we might be re-rolling and hes going to level a warrior so id like to be able to compliment him well. i here necros arent very good, has that changed or is it based on the player for most classes?

Elementalist. Lots of combo fields.
Warrior has a lot of finishers.

Necromancer or Engineer. Warriors have a lot of damage and CC. Necro/Engi has lots of conditions. Both have great survivability and movement. Deadly combination imo.