I like Variks. And Master Ives. He and I are gonna mug Rahool later.
That arc burn part though... We were three warlocks. We died so many times trying different tactics. In the end we just ran around like crazy.
Maybe there are some good tactics out there though?
I've done it twice now, and definitely improving, but I have to say our strategy both times was reliant on a Bladedancer for stealth, and heavily eased by a Defender titan for spot cover. Pure warlocks on that section is a major challenge.
Still, aspects of the strategy we came to rely on could help. First, there's a very defensible wall/alcove you can set up as "home base" by immediately running along the left wall all the way to the dead end you'll find there- with no spawn doors! The initial entry spot out of the airlock is such a chokepoint it's easy to get caught in the arc crossfire, and really can't be relied upon.
Once the team is set up there, round 1 is completely simple, just an ammo pickup round. When Round 2 is about to start, the main mine defuser/Bladedancer runs out all the way to the other side of the map (where the furthest mine can spawn). This is useful not just because if the first mine spawns there it can be capped immediately, but because they'll have a good vantage point to fire back at the wizard(s) that spawn, so they're being shot at from both sides. If the first mine is the closest one to the home base wall, the other two can cap it; any other spawn and the defuser goes for it. After the second one you'll basically know where the third is going to spawn since it can't be either of the first two spots. It's better to help kill wizards ASAP than to dismantle mines early- as long as you get there with 8 seconds or more to spare it can be dismantled. Doing it without stealth of any kind seems pretty rough though- actually, Patience and Time might be a godsend for that round for non-Hunter crews. Once the mines are down, the defused can go back to the wall/corner and help hold out against whatever's left- when you're down to just one or two mobs, then the defused can head back out to that far spot before Round 3 begins.
75% or more of the danger in that round is just being able to fire at the wizards without being killed. A 365 Thunderlord can put in some serious work and may be the right call over Gjallarhorn if you have one for this round.