I was thinking about making this thread for a long time but i cant think of any Hari Kiri. i only got a few so here it is(i hope it makes sense). and some of my Hari Kiri idea is weapon related.

Kabal-He took off his mask, choke to death, fall and die. (since he need his mask to breath)

Sektor (if he's in)- He shoot out his missle and the missle turns around and hit him, making him explode.

Jade-she takes out her staff really fast, place it on her stomach and fall forward. letting the staff stab her.

Bo Rai Cho-He jump up into the air and fall face flat on the ground. But when he landed, he made his stomach flat and thus pushing all his meat and gut out of his back.

Mileena-She takes out her Sai and stab it right into her eyes (both of them), then she fall on her behind and die. (since the blade in the center of the sai is long, when the sai stab the eye, it also stab the brain).

Ermac-He quickly put both hands up to the side of his head (not touching) and then he levitate his head off. then he fall and die.

Nightwolf-He summon the light from the moon and burn his whole body and as the light disappear, he too disappear. (remember his fatalities in MK3, but instead of doing it to the opponent, he does on himself)

Kenshi-He take out his Katana and stab himself (you gotta have at least one character to stab themself)

Tanya-She takes out her sharp boomerang (im not even sure if she has this weapon) she then place it on her neck and begin to whirl it all around her neck. thus making the head fall off. And the headless body just stands there, motionless.

Li Mei-She takes out her Melon and swing it around a 360 (or 180, whatever is quicker), she then let the melon hit her right on her face. then she fall on her back and die, and the Melon is stuck on her face.

Scorpion-He call apon the fires of hell and burn himself

Ashrah-She spin around in a really fast pace. While she is spinning, her body begin to fall apart. First, her arms, then her head, then her body, then her leg stop spinning and fall.

Shujinko-He throust (mispell, i think) his hand into his chest and pull his own heart out, he then fall face flat and die.

Sindel-She took out her Kwan Do weapon and look at her reflection from the blade, she then scream at it and the scream reflect right back at her face, making the head go flying.

more to come. if you have any idea for the characters that we havent seen there Hari Kiri (like scorpion, noob, tanya so and so), you can make some if you want.