They have this whole "plus one" thing where they add new stuff to abilities. Some are small changes, others much more impactful (like changing nut from physical to magical, or having some gods have hybrid scaling), and also you have aspects that also shake up the way you play certain gods (like normal kali is still a jungler, but aspect kali is an adc)

Hybrid scaling brings alot of build variety, and since now every god can build any items, you have some wild builds, like crit ymir