let's see, some of the Evangelion deaths were kinda freaky.
but hands down the weirdest anime i ever saw was one called Cicada(i think) tons of bloodshed, psychopaths and freaky torture stuff.
i forget the anime but the dude started convulsing and gargleing his own blood and his eyes got all dialated and then he started to bleed from his eyes then he got burned to a crisp and turned to ash