In the tower just before Escue's arena, it can be seen hovering around Ferenia with two other Quetzoas.
When Samus enters the room, Escue flies past the windows in the background twice before entering the room and commencing the battle. It attacks by firing a large ball of black energy at Samus, which dissipates if it hits a wall; if it hits the floor, however, it momentarily seizes up before bursting, sending an electric shock across the floor. Escue can also ram Samus or fire small black projectiles that try to home in on her.
Escue's body is usually enveloped in electricity, rendering it mostly invincible save for the Screw Attack; however, it temporarily loses its electricity after using its ram attack. This gives Samus an opening to fire Ice Missiles or Charge Shots at Escue before it recharges itself.
After dealing enough damage, Escue reverts to its Core-X form, which flies around the room and tries to ram Samus. Once it has been hit five times, the shell breaks and the X can be absorbed. Doing so grants Samus the Storm Missile ability. The shrapnel beam fired by Escue may represent it using the item.