Alternate Universes Collide is a story mission in the video game, "South Park: The Fractured But Whole".
Plot details follow.
Head to the right from your house to get to Kyle's.
Note: Take a detour to Stan's house on the way. Randy is outside in front. Talk to him to start the side quest A Randy Mystery. Head inside Stan’s house to find an Antidote Recipe in the kitchen. With this, there should be a new Crafting App on your phone. You can also find Toolshed's Character Sheet inside Stan's Room, and C-Cup Headwear in the master bedroom.
Defeat Alternate Human Kite
The Human Kite 2 from an Alternate Universe is an annoying cheater. Do your best and you’ll come out ahead with little to no issue.
After "defeating" Alternate Human Kite, Human Kite will become a Combat Buddy and ally. Don’t forget to take a selfie with him before you leave, and loot the rest of the house upstairs and use the toilet