About Sony, don't want to be that guy but if for some reason it's really Sony no doubt it's gonna be Kratos. The only option besides him is Nathan Drake.
I'd love Ratchet and Kat as well. The first one at least makes sense because Ratchet is still relevant and has appeared on all Playstation consoles since his debut on the PS2, but Kat has only appeared on Vita and PS4, her franchise seems to be finished and she's not really that popular to became the Sony rep.
Again, I love Gravity Rush and Ratchet & Clank as a franchises, but no way it's happening. Even if Sakurai asks for them when talking to Sony, I seriously doubt Sony would accept. They would want to be represented by some of their more well known characters (like any other company I guess). Ratchet has a chance there, but that's it.
Kratos is the closest thing to a Playstation mascot and the most well known character from their IPs. In terms of moveset Kratos is not really that far behind from characters like Dante in terms of possibilities. Only with the iconic Blades of Chaos you have a really cool concept. Then you have the Leviathan Axe, which works like Thor's hammer.
But again, I refuse to believe Sony is likely lmao