To be fair, if we were going for accurate ninjas, Zed wouldn't be using shurikens at all for combat, they were distraction tools and used more for attacking when unaware. They would also do very little damage and instead apply a long lasting VERY slow but debilitating DoT. also his claw blades wouldn't be anywhere near that long...or a thing at all now that I think about it. Ninjas never had an over the knuckle claw weapon, they did have underhand claw weapons used to block smaller blades and climb walls though, if anything, Talon is more of a ninja then them.
Though Akali is far more ninja like, even going as far to have the proper frame, height, and size for ninjas, a toolbag, though she wouldn't just be spraying and praying with her kunai, hell, actual kunai weren't even used for weaponry unless they were an absolute last resort and instead used more for again, climbing walls, digging, and general utility rather then weaponry. Her kama is ninja like though, as is using a shroud to dance around a battlefield.
You know who is surprisingly ninja like besides attire and attitude, Caitlyn. Even though Hollywood skips over it, Ninjas were notorious for using rifles, incredibly efficient long range killing weapons that were lightweight and easy to carry, yes please, setting up traps to lure people into position, using tools more for escape rather then engage, and one shot kill hits. Like the moment guns became more common practice, ninjas leapt on that shit, and when Ieyasu became shogun, he took his ninjas and trained them to be a police like force to protect him known as the Hyakuningumi.
Edit: I was wrong, they did have an overhand claw weapon called the Tekko-Kagi, but they were more used for defense against blades, and also as a last resort, basically the fact that any of them are even being in melee range of their opponents kind of means that are all shit ninjas.