Doomsday has arrived in Gotham. Batman notices this and realizes he needs help. Lucky for him, a group of people from other universes happened to arrive in Gotham: Dante, Trish, Predator, Hawkeye, Wiccan, Dr. Voodoo, Kraven the Hunter, Ancient One, Chris Redfield, Starkiller, and Lion-O.
Batman invites them to the Batcave for analysis.
Batman: Who are you, and can you help me defeat a monster?
Dante: I'm Dante. Demon hunter. My weapons can hurt demons, and I've got a healing factor. Incalculable strength. If I'm ever in serious trouble, I can go devil trigger, temporarily boosting my strength, speed and durability. With enough friction, I can move 17,000 miles per hour.
Trish: Strong enough to throw a motorcycle, I am Dante's occasional sidekick, my 2 handguns, my blade, yellow electricity projection, and I have my own devil trigger.
Hawkeye: Skilled archer. Explosive arrows, zip line arrows, adamantium arrows, and an arrow that turns into hundreds of other arrows. I'm fast enough to catch arrows in my hands, even with my eyes closed.
Batman: What's adamantium?
Hawkeye: The strongest metal in my universe
Batman: How strong?
Hawkeye: Strong enough that even the Norse God Thor has trouble breaking it. No joke
Dr. Voodoo: I can fly, control ice, water, and fire, I am immune to burns, and I can summon smoke. I can also teleport, and communicate with Loa, African tribal gods.
Kraven: Shotgun, nets, bolas, traps, gases, spear and a blowgun with poison darts.
Wiccan: Can fly, summon objects from nowhere, heal others, manipulate light, teleport, telekinesis, and can use concussive energy blasts.
Ancient One: Chi, and sorcery
Starkiller: I've defeated strong ones, my red lightsaber, and I can use force choke and lightning.
Lion-O: The sword of Omens has incalculable power, a tractor beam. My gauntlet can scratch through stone, has 3 grapple hooks and a smoke screen. I'm the strongest and fastest of my species. Predator over here can turn invisible, fire plasma, and use a heat vision scanner
Batman: Hmm... We got to get ready. Doomsday has defeated people who are strong enough to defeat all of us working together.
Dante: Well, let's strategize wisely
Batman creates a plan, and the team is listening.
Batman: Ok, Doomsday will walk onto a platform on the streets of Gotham. My explosive gel will blow up, and he falls down the hole. Lion-O and Kraven will go together at corners in case he escapes. Trish, you, Ancient One, and Hawkeye go together. Dante, you will go with Wiccan, Dr. Voodoo, Starkiller and Predator
Starkiller: Well, team. We gotta be careful like the boss said.
The time comes, and Doomsday falls into a hole. Doomsday climbs out with his strength. Voodoo and Batman decide to use smoke to distract him. Wiccan jumps in and uses the light to blind Doomsday. Dante shoots him with ebony and ivory, and Starkiller electrocutes him.
Doomsday: I will destroy you all!
Starkiller throws the lightsaber, but it does little damage.
Lion-O uses the smokescreen, and Doomsday runs into Trish's electricity mine. Ancient One teleports him to Joker's building from Arkham City. Hawkeye fires his arrows, but they do no damage.
Dante: He's not like the other demons I've fought. Let's try the hard way!
Dante uses Yamato, which launches Doomsday all the way to the GCPD building. Doomsday is still alive. Dante decides to go Devil Trigger, and beats up Doomsday, and shoots him in the eye with Ebony, and Lion-O finishes off Doomsday by stabbing him in the face with the sword of Omens, and Starkiller slices off his head.
Batman: He might come back alive, immune to what killed him. Let's destroy the body.
Trish shoots the head and blows it up, and Starkiller slices up the rest of the body into pieces and blows them up with the force. Dr. Voodoo washes away the blood with water.