A very good addition that brings additional content to the game.
Its essence is a trinity of especially dangerous and harmful aliens, each with its own specifics, strengths and weaknesses. These comrades like to appear at the most unfortunate moments during ordinary missions. Which sometimes gets annoying.
Each one lives on its own territory and, after a chain of special reconnaissance missions, will be available for the final battle. What is especially valuable is that in addition to the fact that the appearance of the killed in our operations stops, after the enemy there is also unique loot. Which turns a properly pumped up fighter into a little angel of death.
The DLC is high quality and quite voluminous. If the question arises whether to take the second part along with it, take it.