Vengance for Davian Thule

First things first, the closest beacon is to your north. Head that way. Keep an eye out for those nasty spore projectiles flying around and just cut your way through the swarm to reach it.

Once you've grabbed that first beacon, your next objective is a strategic asset nearby. You'll run into some warriors blocking your path. Use your ranged units to deal with the smaller enemies, but send Thaddeus in to drop on the warriors. This'll keep them busy and stop them from blasting your squad. Have the rest of your team push up behind him, clearing out enemies as they advance. Securing this asset gives you a significant advantage.

With the asset under your control, start slowly pushing outwards. Your goal here is to thin out the Tyranid numbers as much as possible before you need to pull back and heal. Grab up all the beacons you can find and take down as many Tyranids as your patience allows – all that extra experience will really help. Just stay sharp and be mindful of the Warriors you encounter; they're no joke.

Now, about the Warrior boss. This guy can be a real pain, especially at lower levels. He's got a ton of health and defense. Your best bet is to spread your people out. Keep your gunners behind cover, like the stone walls to the north and south if you can manage it. Use your Force Commander to draw the boss's attention and lure him closer to you. Thaddeus should engage in melee too, but keep him ready to assault jump out if he starts taking too much damage. Honestly, none of his attacks are game-enders if you've got your rally ability up and a healing kit ready, so don't sweat it too much.