Jacob, in his werewolf form, would be more likely to directly confront Jason. He's used to fighting against threats, and his strength and speed as a werewolf would make him a formidable opponent. However, he might be a bit overconfident at first, not fully realizing the unique danger that Jason represents.
Ruby's speed might increase even more due to the sense of danger from the Friday the 13th elements. She could be constantly on high alert and her scythe attacks could be more erratic and fast - paced.
One possible plot could be that the vampires from Twilight somehow end up in the world of Friday the 13th. Maybe they get transported there by a strange magical event. The vampires' powers would be a new and terrifying element in the already spooky Friday the 13th setting. They could either be enemies of Jason or form some sort of uneasy alliance with him.
First, decide which two or more universes you want to cross over. For example, if it's 'Friday the 13th' and 'Alien', think about how the two different types of horror can blend. Then, introduce the setting. If it's at Camp Crystal Lake, describe the spooky atmosphere. Next, bring in the characters. Start with a character from one of the universes, like Ripley from 'Alien' arriving at the lake. Then, build the conflict. Maybe there are strange alien - like creatures emerging from the lake, and Ripley has to team up with Jason (in a strange way) to face this new threat.
One idea could be a crossover with 'Nightmare on Elm Street'. Freddy Krueger could invade the 'Friday the 13th' world and start terrorizing the campers. Jason Voorhees would then have to face this new threat. It could be an epic battle of two horror icons.
In a crossover, the Cullens from Twilight could try to blend in with the Sons of Anarchy community. Carlisle, being a doctor, could offer medical help to the gang members, which would start to build a relationship. However, the gang's illegal activities might put the Cullens in a difficult position. Esme could try to be a mother figure to some of the younger gang members, but the cultural differences between their two groups would make for an interesting dynamic.
Harley Quinn would likely be very curious about the vampires in Twilight. She might approach them in her usual zany way, not fully understanding the danger they pose. For example, she could try to make friends with Emmett, seeing his strength as something fun. Meanwhile, Bella would probably be a bit scared of the Suicide Squad at first, especially someone like Killer Croc. But as she gets to know them, she might see their humanity.
There could be some interesting friendships. Isabelle from The Mortal Instruments might befriend Alice from Twilight. They are both strong and stylish female characters. Isabelle could show Alice some of her cool Shadowhunter weapons, while Alice could share her visions with Isabelle. Alec from The Mortal Instruments might be a bit more reserved in his interactions, but he could find common ground with Carlisle in terms of their more responsible and moral outlooks among their respective groups.
The characters from Twilight are used to a modern - day setting with some supernatural elements, while those in Lord of the Rings are in a more medieval - like fantasy world. The vampires in Twilight might initially seem like powerful and feared beings to the people of Middle - earth. For example, Aragorn might be cautious around them, not fully understanding their nature. The hobbits, on the other hand, could be both curious and a bit scared. Bella could form an unlikely friendship with Arwen, as they both are strong - willed female characters. The Twilight werewolves might have an interesting dynamic with the Rohirrim, as both are associated with a sense of loyalty and protectiveness.
Sakura would be frightened but also determined to protect her friends. She might use her medical ninjutsu to try and counter any negative effects the Boogeyman has on people. Shikamaru, being the lazy but smart one, would first analyze the situation. He'd come up with a plan that involved minimal effort but maximum effectiveness, like using traps to catch the Boogeyman.
Ruby would probably be both scared and fascinated. She's always been curious about new things, and Godzilla is definitely something new. But she would also be worried about the destruction it could cause. Weiss might be more cautious and initially see Godzilla as a threat to the order in Remnant. Blake would likely be on guard, observing Godzilla's behavior to see if it's truly hostile or not.