Droma is spawned occasionally by Trauma. Trauma will also Drain from Droma, eventually killing them. Once all Dromas are gone, Trauma will use Mega Pulse Cannon. Dromas themselves are capable of using a smaller version of said attack, aptly titled Mini Pulse Cannon.
In its concept art, Droma was known as Fannel System(ファンネルシステム, Fanneru Shisutemu?, lit. Funnel System).
Droma's Japanese name is from French alignement meaning "alignment." This is most likely in reference to stone alignments to continue the megalithic theme and allude to there being multiple beside Trauma.
Droma may be a portmanteau of "Drone" and "Trauma."