Cloud AU's

Water?

It was a fight with the Varia that seemed to escalate thanks to the Wrathful Sky and the Arcobaleno (mostly Reborn's) sun-high ego.
Tsuna was trying to stop them as his own Guardians joined.
They were on Mafia Land for Vacation and bonding - honestly, what should they have expected with their line up?

It was Reborn VS Kyoya VS Mukuro Vs Xanxus VS Colonello VS Tsuna VS Verde... Fuck it, it was a free-for-all Battle Royale!
Meaning even those who tried to stop them became part of it (at least it helped Tsuna/ those with too much paperwork to get rid of their stress and stretch).

...Until Skull, who was trying his best to escape undetected and away from them, got shot by Colonello's flames and was unceremoniously blasted into Water... The weirdest thing was his screech upon contact and Tsuna temporarily fell down holding his pounding 'Smth just got triggered' - migraine™.

He lookeded around warily, trying to identify the cause and reason.
Seeing how they all either didn't care about the small disturbance -or Skull in general-, he went to Reborn quietly as if walking to school (on time without being chased or naked) without an ounce of Killing Intent escaping him before uppercutted him in the jaw with a Big-Bang-Axle.

Most of them finally stopped - they froze, really, as he is the visibly biggest threat - at seeing the Reborn, greatest Hitman in the World, Sun Arcobaleno as well as undisputed leader of the Arcobaleno, go fly through the air and a slowly-emitting dark aura coming from his younger student.

Seeing as they all finally stopped, Tsuna looked around and saw that Skull wasn't anywhere.

—Correction, he was on a small purple island on the water?

On closer inspection it was his octupus Oodako that caught him. Tsuna flew over, his Rain & Storm following behind him shortly, meanwhile Reborn was rubbing his jaw (his student had gained a mean punch). He looked to where said dame-Tsuna was going -flying- and saw his lackey.

Upon arrival, Tsuna saw Skull in a daze looking into the water and for a moment his eyes were a glowing green. Seagreen, not the electric lightning variant he knows from Lambo and Verde.

Skull shook his head, snapping out of it as his -purple- eyes refocused on Tsuna and Oodako.
"Hehe, the Great Skull-sama is Fine! -Now if you'd excuse me..!"
He was shivering but spoke eerily calm, quieter than usual, with a primal, raw tint to his voice that distinctly reminded him of his own Cloud. It concerned him as much as it confused him, his migraine/ HI™ not helping identify what's giving him the weird vibes.

They went back to the beach and all eyes were on the Cloud and Tsuna. Reborn and Xanxus went towards Tsuna.. but suddenly Kyoya got his tonfas out and charged at Skull?!

"Oya, Oya..? Kufufu, Skylark?"

"Welp, he's dead, Kora."

"Huh?/ What-?"

Was questioned by the three groups. Why would Hibari, who stays away from weak Herbivores, and crowds, suddenly show such hostile behaviour to the 'Weak, herbivorous' Cloud? Even Fon,
his uncle, couldn't understand his nephews sudden strange behavior.

Yet despite expectations Skull dodged every single hit thrown at him from the younger Cloud! They were now closely watching the exchange and, as expected as it was that Skull would try to dodge, they didn't think he actually could.
Upon closer inspection, Kyoya looked disgruntled while hitting at the older Cloud. What did the other do to get him that upset?
The only one who could do it on a daily basis and seemingly without any effort was Mukuro, but did Skull do something without anyone noticing??
...Was it a territorial thing?