(I'm going to use the English covers.... Except for InSaNiTy... I can't find a good English cover for that one)

Warning, feels ahead. Like, a lot of feels. Seeming I think I'm only using the sad Vocaloid songs... Except Wildfire. That shouldn't give too many feels. Unless you think of it as 2p DeNor. Than it might give a few feels:

Kiku- Lost One's Weeping

I know that this song is about too much pressure school wise... But, I think you can take it as too much pressure on one period.

Matthew- Goodbye

"And I'll be forgotten in time."
... yeah.

Ivan- InSaNiTy

Must I explain?

Arthur- Echo

This is more so based around his colonies leaving him time and time again. And just when he's pulled into the light, something bad seems to happen. Events can change faster than the channels on TV...

Lokki- Wildfire

He's a freaking fire-obsessed 2p....

That's all I got so far...