what do you think owuld be an appropriate epic level feature at 27. something like the damge on the call the hunt increases or something else?

The quoted entry in incomplete. Here's the full entry: "Claws. Each of your hands transforms into a claw, which you can use as a weapon if it’s empty. It deals 1d6 slashing damage on a hit. Once on each of your turns when you attack with a claw using the Attack action, you can make one additional claw attack as part of the same action."

Notice how it says you can only use your clawed hand "if it's empty". So no, you can't use your claws to swing a great axe as part of the effect.