This event contains examples of:

All for Nothing: The Mukuroshu Man tells Yachiyo that even if they open up the Realm of the Dead, his wife's soul won't return. Saiga killed his master for a lie.
Breaking Old Trends: A special map with rescuable houses is normally reserved for Special Training in Defense events, but here it's the final regular mission.
Faking the Dead: Saiga feigns death in the last chapter so he can get close enough to strike the Mukuroshu Man, bypassing his zombies.
How We Got Here: The event starts with Yachiyo and Saiga about to fight each other, then rewinds to days earlier in the Halidom to how it got to that point.
Human Shield: The Mukuroshu Man uses Dyrenell zombies as meat shields anytime someone takes a shot at him.
No Name Given: The Mukuroshu Man is this all through the story.
Off with His Head!: Yachiyo plans to do this to the Mukuroshu Man after he brags about making Saiga kill his master.
Yachiyo: "No! Move! Outta my way, ya jerks! I'm gonna take that cat's head off with my own hand and mount it on my mantle!"
Sequel Episode: This continues the Mukuroshu plotline started in "Cursed Connections."
You Killed My Father: The Mukuroshu Man reveals that Saiga was the one who killed Yachiyo's grandfather, who was also his teacher.

Recap / Dragalia Lost Shadow Of The Mukuroshu