As part of the Karu art, Tumo has also worked up some tools. Not weapons mind you, tools! Soulcarvers are the top crafters of Garuda after all.
Their axes are often very ornate with each crafter letting their axe speak for them. Each piece of work has the personality of the crafter in it, and so too does their tools.
Mind you though this is all decoration. None of these changes actually make the tool stronger. But it does make it more familiar and easy to use for the crafter.