It's so cool how almost every single GoW character has it's own impressive feat. It's either High 3-A, low 2-C or 2-C feat.
In terms of top feats of characters on their own;
Greek
Zeus: High 3-A (Via roaring)
Ares: High 3-A (Via roaring)
Poseidon: Low 6-B via hand gesture
Hades: Low 2-C (via embodying the Underworld)
Helios: 2-C (Preventing Morpheus from merging with the mortal world, fighting off Nyx etc.)
Hercules: 2-C (Held the Greek cosmos)
Atlas: 2-C (Held the Greek cosmos)
Cronos: Low 2-C (Birthed time)
Gaia: Casual High 6-A (Breathed continents into and out of existence)
Uranus: High 3-A (Via having the mortal universe punched out of him)
Norse
Odin: 2-C (Killing Ymir and making 6 realms)
Thor: 2-C (Splintering Yggdrasil)
Jormugandr: 2-C (Via shaking the Nine Realms)
Nidhogg: 2-C (Gnaws on Yggdrasil's roots)
Nidhogg's babies: Low 2-C (Would devour the Nine Realms)
Garm: 2-C (Would chew through the fabric of the Realms and cause their collapse)
Sutr: 2-C (Shook the Yggdrasil to its roots)
Base Valkyries: Low 2-C (Their magic tears apart the fabric of whole Realms)