While being a provocative series, it definitely shows a few scenes that are just frightening: Toys that have blades emerging from their bodies, the black monster Kain who seems to do almost anything including the ability to turn into a black dragon demon, an evil Jurai knight decaying rapidly into a skull-faced corpse which you have can fun with being that it was shown every time ''Tenchi'' starts, the earth being cut in half, Hotsuma turning into a monster, the eldritch-y dream realm (not the one with shards, but a weird black and white Picasso drawing type place) of Yugi, Kagato (especially his OVA incarnation), Ryoko's bestial form, and Sakuya being absorbed into Yugi against her will....Have fun with that.
Let's elaborate on Kain. He's a writhing mass of dark energy with a sadistic personality, takes on a pure white mask with a Slasher Smile, and later turns into a monstrous dragon, demon, shark thing.... one of the first things he does when he lands on earth is rip a guy in half and throw him at a small group of teenagers. Sheesh.
Yuzuha's first appearance in the "Daughter of Darkness" film. We first see her gleefully preying on three Juraian children. Transforming them into food, which she happily eats without a care. It's actually rather creepy how casual and nonchalant she is about it.
In the finale of Tenchi Universe, Kagato has two elite guards who Azaka and Kamidake respectively. While intimidating in appearance, especially Kamidake's opponent with his slit-eyes with black sclera with red irises on closer inspection and eerily pale appearance, it's their iconically gruesome deaths that make them stand out, with both rapidly aging to corpses when defeated, but especially with Kamidake's opponent who goes from creepy to a skull-faced corpse the second he dies, which was showcased whenever Tenchi Universe was promoted on Toonami.
