So Kayn has 12 Abilities?

No. He has 4. Where are you guys getting this information that he can just switch between forms at any moment?

Technically no. His abilities do the same thing fundamentally in each form, and his passive transforms him permanently for the rest of the game after he activates it. His Q, no matter which form he is in, is a dash that deals damage at the end in an AoE around him. It actually doesn't have an added effect in Shadow Assassin form. Darkin form only changes it by making it heal him. His W is, in all forms, an AoE line of damage and some form of CC. In Shadow Assassin form, he gets more range and can move while casting and it will leave behind a Living Shadow to continue the cast. In Darkin form, it gets a knock up instead of a slow. His E, in all forms, lets him run through walls, gives him movement speed, and heals him the first time he enters a wall. In Shadow Assassin, it does something extra that I'm brain farting and forgetting right now. His ult, in all forms, lets him attach to an enemy he recently damaged and deals more damage after a delay. In Shadow Assassin, it gets more range. In Darkin, it gets % max health damage and a heal. His Q only gets an added effect in Darkin form and his E only gets an added effect in Shadow Assassin form.

I don't think Kayn can change between his forms. He can choose which one he turns into based on who he fights though.

base form has to farm orbs (similar to elementalist lux)

then can transform into blue or red based on orbs collected.

blue/red form has enhanced moves for the passive and qwer respectively. they're not "new moves" just modified moves.

sort of like how khazix can evolve only kayn does it all at once.

once you choose your form you cant revert.

Really its a publicity stun He has the same kit but a bit upgraded with some different bonus

someone hasn't been paying attention.

He has 4 abilities,2 of them have 1 variation and the other 2 have 2 variations. But in the end the abilities don't change that much.

Mathematically he has 10.

Q Q darkin W W darkin W shadow E E shadow R R darkin R shadow