“Zetsuentai“ means “insulator“ and this performance is from DEG’s The World You Live In [Behind Closed Doors] concert. The song was requested by Andy xRRRx and long ago, before this performance existed, by Manaatti. Here it finally is, I hope you like it!
Translation by me.
Annotations:
“Will it be a life where you could laugh?“ - Or “Will it have been [...]“. Also, it really depends on the reading whether this is simply “a life where you could laugh“ (positive) or maybe a “laughable life“ (which would be negatively connotated).
“Just please be by my side“ - The literal grammar is “I want you to be by my side“.
“Without reason - I was continually destroyed“ - I understand this as referring to himself, however it could theoretically also refer to “this time“, mentioned in the line before, or something else.
“’Believing - Is all it is’“ - In