The first time one appeared, it was alongside the other four MegaZord ktypes at the time. Miho Nakamura was unable to identify its signature at first, as it had never appeared from Hyper Space but Toru Morishita was able to identify its make, likely from Energy Management Center files. Go-Buster Ace was able to destroy it, throwing Enter into the water.
The second Epsilon the Go-Busters faced was during the Go-Busters' raid of Hyper Space. Enter uses it to go up against Red Buster and Go-Buster Ace. The MegaZord Epsilon was destroyed in the same episode.
It was assumed that Enter had died in the resulting explosion. That, however, was later proven false.