So I plan to add Mortal Kombat as part of Project Vanguard, and here's some ideas for their fatalities.

Bravestorm

Fatal Blow

Weather Forecast (Invincible and Mahito)

Ethan blasts a lightning bolt at Mahito. Invincible then rapidly punches Mahito before headbutting him hard that his skull breaks. Ethan then slashes Mahito with his lightning blades, before creating an ice wall, and slams Mahito onto the wall, breaking his spine.

Fatalities

Shock & Drop (Homelander)

Ethan creates his electro blade, and slices Homelander's arms. He then slices his stomach, causing his intestines to fall out. He then charges his arm with electricity before electrifying his guts, as Homelander is electrocuted, the flesh around his face melts and his eyes pop with lightning coming out of it. Ethan then holds him up and smashes his head into the ground, completely crushing it.

Cold Hearted (Signora)

Ethan tears out Signora's heart right. He uses his powers to freeze her heart into solid ice. He then kicks her to the ground, before repeatedly smashing her face in with her frozen heart, before delivering a final blow that shatters her frozen heart and crushing her face.

Forcewave

Fatal Blow

Slammer Time (Denji and Jinx)

Rachel stomps on the ground creating a shockwave that sends Jinx back. Denji then charges at Jinx, before grabbing her and slicing her head with his chainsaw head. Rachel then grabs her by the throat punching her rapidly on the face before slamming her onto the ground, shattering her ribs.

Fatalities

Good Vibrations (Dimitrescu)

Rachel grabs onto Dimitrescu, before vibrating her body so strong that the vampire lady's skin begins to peel off, leaving her nothing but a bloody muscles as she screams in pain. She then grabs her by the legs, and splits her in half, before throwing her body onto the ground.

Crushing It (Springtrap)

Rachel knocks Springtrap onto the ground, before grabbing him by the head and feet, and begins to pressing his entire body. Springtrap screams as blood begins to pour out, his eyes popping out and bones and internal organs being crushed. Rachel then stomps on Springtrap, completely crushing and killing him.

Nightlock

Fatal Blow

Lights Out (Yamamoto and Vergil)

Henry blasts a beam of darkness at Vergil. Yamamoto then summons his Ryujin Jakka which burns Vergil, before slashing him at the chest. Henry then summons many tentacles of darkness then wraps Vergil around. He kicks Vergil on the chest multiple times, before landing a two-footed kick at Vergil's skull.

Fatalities

Fun in the Shades (Akechi)

Henry creates a sphere of darkness around him. Henry then enters the sphere, where a brutal sound of ripping and squelching can be heard. Akechi's limbs begin to thrown out one by one, before the darkness fades, revealing Akechi's mutilated corpse. Henry then throws Akechi onto the ground, as Akechi tries to crawl away, Henry stomps on his head, crushing it.

Shadow Games (Anissa)

Henry gouges Anissa's eyes out, as she screams in pain while blood pours out from her eyes. Henry then grabs onto Anissa's face, where shadows enter through her eyes and mouth. Many tentacles of darkness pierce out from her body, before tearing her apart completely.

Starglass

Fatal Blow

Through the Looking Glass (Ahri and Crow)

Alice throws shards of glass at Crow. Ahri strikes Crow with orb of light, before striker her with her tails. Alice then creates mirror-like portals which her duplicate appears, slashing her with a broken mirror piece, before slamming Crow through the portal which shatters and cracks her skull.

Fatalities

Shower of Glass (Geto)

Alice summons many shards of glass and mirrors around Geto. The shards begin to pierce around him until his entire body is stabbed with shards. Alice then holds up her hand, spinning Geto's body before his body explodes.

All That Glitters (Reze)

Alice creates a giant mirror, which refracts a powerful beam of light that burns Reze. She then breaks the mirror, before grabbing each piece and stabbing on her on the head, before the shards glow and explodes her head.

Hemocyte

Fatal Blow

Taste of Blood (Zhongli and Jetstream Sam)

Joshua fires a ball of blood at Sam. Zhongli then strikes Sam with his spear before summoning a giant rock that crushes Sam's ribs. Joshua then kicks Sam's legs, before stabbing him with his blood spike through his mouth.

Fatalities

Pump It Up (Bambietta)

Joshua stabs Bambietta in the heart, before pumping his blood onto her body. Bambietta's body begins to blow up like a balloon, with blood leaking out of her mouth, ears, nose, and eyes, before she explodes completely with blood and guts.

Paint It Red (Reaper)

Joshua grabs Reaper, before vomiting a wave of blood at him. Reaper begin to melt, as his body violently melt away. His upper body now completely melted with only some of his skeleton remaining, Joshua kicks the skeleton and shatters it.