Keyblades of Chaos

Honestly I could see them being friends in God of War Ascension, 1, and Norse. The timing of when Sora and his friends appears being imperative. Since this is KH2 Sora

GOW Ascension: Them being the friends Kratos sorely needed in the Furies Affair especially after Orkos' death. Or Sora somehow using the Keyblade's powers to non lethally break Kratos' Oath to Ares which was stuck on Orkos. Here he and his friends along with Athena would actually think about taking Kratos along with the Chosen of the Kingdom Key to help with Organization 13 since their plans serve to further screw up the worlds along with preparing Kratos for the brawl with Ares. Sora and the gang helping him cope and move with all he's done throughout KH2. Perhaps Kratos grows into the Younger version of the Team Dad we see in the Norse days but quicker. Maybe being a Sink or Swim Mentor to the Chosen of the Light to contrast Yen Sid and Mickey's Stern but Careful mentor.

GOW Chains of Olmypus: Due to Morpheous' sheningans, allies of chance at best. Perhaps they'd bond over the whole affair. And prevent Kratos from going to Elysium Fields or at least forfeiting his power to go there due to pointing out if Persphone destroys the pillar Elysium and Calliope go down the drain as well.

GOW 1: A therociatal Superman and Spawn dynamic. After a misunderstanding and a resulting fight that Sora and Friends would provide a even match, perhaps even stalemating the Spartan. Learning the situation and seeing Organization 13 is exceberating the issues at hand with Ares. Perhaps Sora and friend heading into the Underworld and helping Kratos breakout and hopefully saving the Ship Captain in the process.

GOW Ghost of Sparta: That infamous act with the Princess probably has a 50 percentage chance of happening along with Poseidon's famed Altantlis sinking. But if it's done there's a good chance Sora, Donald, and Goofy would have a very tense dicussion with the Spartan regarding this quest. After the revelations of Athena's part in the kidnapping of Deimos. A shaky relationship after these events

GOW 2: NOPE! Probably part of the force that took him out before Kratos was a sore loser and hit the reset button. Allied with Zeus to take him out. And saving Athena and finding out the Pandora Box's contents are screwing with all the gods.

GOW 3: NOPE! Hell they'd be in Kratos' way and only spared after a hard fought battle(Sora's Sheer Adaptablity, Reaction, and Form Changes vs Kratos' Greater Experience, Greater Skill, and Magic) because of Pandora due to her playing Kratos' consciousnce like Jiminy or Organization 13 interference for their schemes. They'd be especially angry after Herc's death(Doppelganger or Dimensional Counterpart gets the Same Sentiment trope).

GOW Norse: Kratos' reputation procedes him but Sora would connect with him due to him seeing he has changed massively or is different from his reputation would have people think and would befriend Atreus and him later on.

Depends on when they show up