ADVENT MECs are large robotic units that provide heavy support for other ADVENT units. They are similar to the XCOM MECs of Enemy Within, but are completely robotic in their exterior, and are a glistening white. They carry a variant of the Magnetic Rifle highly increased in size, and presumably damage. Additionally, ADVENT MECs have an automatic grenade launcher on their back, allowing them to fire a fusillade of micro-missiles in an AoE attack. ADVENT MECs are heavily armored, and have superior health to ADVENT troopers, as well as damage reduction in the form of armor points. As robotic units, they are vulnerable to hacking and having control of them given to XCOM for a short while, although a failed hack will increase the MEC's accuracy and defense.
ADVENT MECs can cause AoE damage with micro-missiles. ADVENT MECs are also capable of laying down Suppression fire on enemies. It is possible for properly upgraded Specialists to temporarily hack ADVENT MECs, although there is a chance of summoning reinforcing MECs if it fails. MECs have a higher amount of health than ADVENT troopers, but seemingly not much compared to late-game Enemy Within MECs, suggesting their equivalency to the MEC-1 and MEC-2 in strength. ADVENT MECs are armored targets, reducing the damage an attack deals, but are vulnerable to shredding.