Because you like Mother Brain in Metroid
Hank McCoy is a quintessential nerdy scientist but with a few rather unconventional physical attributes. See them in X-Men Series.
They say they saved Adam Jensen by turning him into a cyborg, but he's not sure saved is the right word. See them in Deus Ex Series.
Big Boss is a disillusioned mercenary commander who wants to create a world for soldiers (and soldiers alone). See them in Metal Gear Series.
No one has seen The Mandalorian without his helmet since he swore the creed. See them in The Mandalorian.
Born and raised in the darkness, Bane is determined to have the city totally under his control so that he can demolish it. See them in DC Extended Universe.
Wanderer is a Soul, a parasite sent into a host to take over their body, extracting information from them and colonizing their species. See them in The Host.
Ultron is security software turned evil mastermind. See them in Marvel Cinematic Universe.
Count Olaf is a traveling actor, except he can't act and his homicidal tendencies make finding work pretty difficult. See them in Lemony Snicket's A Series of Unfortunate Events.
His name is Chucky, and he's your friend till the end. Hidey-ho! See them in Child's Play.
Keeping your cool is just as useful in the underworld as in war, and Michael Corleone is stone-cold. See them in The Godfather.