Gurus in the late Goryeo dynasty try to obtain a fabled, holy sword, and humans in 2022 hunt down an alien prisoner that is locked in a human's body. The two parties cross paths when a time-traveling portal opens up.

Ryu Jun-yeol
as Muruk

Kim Woo-bin
as Guard / Thunder

Kim Tae-ri
as Ean

So Ji-sub
as Moon Do-seok

Yum Jung-ah
as Madam Black

Jo Woo-jin
as Mr. Blue

Kim Eui-sung
as Jajang / Doctor

Lee Hanee
as Min Gaelin

Shin Jung-keun
as Right Paw

Lee Si-hoon
as Left Paw
MovieGuys
I found it difficult to relate to Alienoid. I suspect the reason is cultural. Some things work across cultures and other's don't. I found Alienoid simply too strange. It has an off beat personality too, which really didn't help matters. The slapstick humour fell flat, too. Giving characters name...