It starts by firing bursts at the ground in random spots, then doing the same against the ceiling. After it does these attacks, it will angrily fire a barrage of shots all over the ground area. It will then repeat it's chain of attacks.
There is a hover booster that can be used to access a rail above Spark for attacking it.
While playing as Milla, she can find and ride Sparky until the fight against the Shade Beast. It has a green and orange color scheme, and an eye similar to Milla's. Shooting up with the it while moving will damage Milla.