Just bought it and been doing some LL3. I've found several counters to Berserkers - Goblin 1 Puppet System/Eject Power Cores on a Sensor range 20 Death's Head. Puppet walk one Berserker next to the other, Bracketing Fire so they are both Impaired, then get them whacking each other (for full damage since Impaired). Follow up by teammates taking advantage of the Impair for full damage. Sets off Tactician 3 etc. My current loadout (Overpower Caliber on everything):
Death's Head 2 Goblin 1 Heavy Gunner 3 Combined Arms 2 Infiltrator 1 Heavy Machine Gun Assault Rifle/Light Nexus a basic Neurolink+Perfected Targeting+Core Siphon build
Tokugawa 2 Pegasus 1 - uses Tactician 3 Nuclear Cavalier 3 Smartgun/Smartgun Light Nexus/Light Nexus. In the Danger Zone and running Limit Break. Plasma Sheath activates and turns all bonus damage to Burn. One shot is Opcal 1d6 +Nuclear Cavalier 1d6+Limit Break +3 bonus damage (burn), and Limit Break bonus dmg applies to all attacks, including the 1/2 dmg Tactician 3 reaction. Smartgun ignores cover and has 2 Advantage (Tactician+Smartgun) so I can tank Impaired and still stay Accurate. Hunkers out of line of sight if possible and shoots from safety. Feels really broken!
Everest Swallowtail 3 Heavy Gunner 3 Combined Arms 2 Infiltrator 1 Heavy Machine Gun Assault Rifle Light Nexus/Oracle Light LMG - this guy has the Athena NHP. Athena gives Blast 3 area cancels cover, prevents starting up Invisible/Hidden and if the enemy ends their turn there, adds free Lock-On and cancels Invisible/Hidden. And lasts the whole fight for one Quick Action.
Everest Barbarossa 3 - Tactician 3 Nuclear Cavalier 3 - Siege Cannon Mortar. Fire, next round use Everest Initiative drop Reloader Drone if desired etc. Will rework it so there's more of a challenge, probably to a Monarch Missile platform instead.
Tactician 3 plus Smartguns and Mortars is very very effective for focus firing to the point the high value enemies are guaranteed to wipe.
Tentative plans for higher LLs is maybe Reactive Weave (Metalmark 1), Dusk Wing 2 for Flicker Field Projector (50% miss chance on next one attack after move/boost) or Mourning Cloak 2 for Singularity Motivator (reaction teleport 1d6 on a hit). You could Brace, turn Invisible for free, move Speed for free, and Reaction teleport 1d6. Or just Teleport 1d6 if hit damaged. Nice.