Apparently, Wraith-type monsters were weak to light-based attacks. A flash of bright light would stun them, tearing off their dark cloaks and revealing their true forms.
Naturally, Eren bought a Flash Grenade from the system shop instead of learning a light magic, which displeased Useless again.
The results?
Highly effective.
But also disturbing.
Once the darkness was stripped away, their real appearance was revealed, A humanoid figure with an upside-down face—eyes on the chin, mouth near the forehead—and a lower half composed entirely of writhing tentacles made of rotted flesh.
Eren had two reactions.
One: "Disgusting!"
Two: "Also kinda cool…"
Like a hard core gamer, the guy admires monster's design, like the ones from a dark-themed RPG.
And it wasn't just the Wraith Ghouls, as the next monster he encountered was also cool and disgusting.