Jeanie and co. didn't know the kits were in there. Future L_G must've slipped them in when he was building the Interceptor II. If you're wondering how he found them, he came across a Pawn Shop in the Shadow Realm while he was building the ship that your monster has in it's grasp. Hope that clears things up.

Beth fires an Ultima Cannon shot at the thinnest part of the tentacle, blasting it into two parts. Tentacle takes 57932 HP damage.
The Helmsman flies the Interceptor II away from the beast, at a slow enough speed so that it won't detect it. I hope.