The Expanded Arsenal Add-on for Alienation has 4 trophies - 3 bronze and 1 silver.
Hit at least 20 enemies with a single fully charged Collapser shot
Get the killing blow on an enemy with at least two Devastators' beams hitting each other.
Hit at least 6 living Xenos with a Vortex Grenade in Pripyat amusement park
Have all different primary weapons in your inventory, with at least Rare rarity