Aiya’s witch bolt hits at the same time that Tails steals the hammer right off the Tinker’s belt. He gains a direct connection to all the secrets of the workings of the universe stored within the hammer.
The Tinker steals back the hammer and begins siccing his various creations on the party.
The Tinker assembles a huge mech around himself from the bits on his piles. He fires pieces of his armor as shrapnel at the party.
Stelar rises from one of the piles of stuff and fights…
Also, here are the comments from Joyful Steel, the angel of the edge, on what he'll need to make you a powerful enough weapon.
"Every artifact needs a Core. A base. The heart that the rest is built around. Yours will need to be old. Ancient. Or unbreakable. Satrina is the First Witch. Her magic is primeval. Fossil wood, primal steel, a strong enough song...The bones of the earth, or the silver of the stars."
"The Craft is the change. The heat and flux that makes one thing into another. I can manage the Craft, but I can't create it from nothing. If you can restart this forge, you'll have a chance. It'll need fuel. There used to be a planar gateway deeper in the city, but fire isn't the only option. Change comes in many ways."
"You'll need something to cure it. To set the change and fix its shape. Water. Blood. Music. Poison. Whatever it is, it needs to pierce the heart of the Daughter of Flame."
"The Catalyst is the spark. The element of enchantment. Souls. Secrets. Life. Places of power. Legends. I don't have one handy, not for something of the strength you'll need. Her will is older than the stars, and built in each of you."