This is a pretty specific offshoot from the core of the class so far, so I assume it would probably need to be like a class archetype or something, but a vision popped into my brain and I had to share it. The way the Inventor custom-crafts weapons and armour, especially adding non-magical versions of elemental damage to their weapons, or gaining resistances to their armour, reminded me of how in Monster Hunter you have your weapons crafted with the elemental abilities of the monsters you slay.
I was thinking it would be really cool to have an Inventor type which could perform similar feats of acquiring monster parts or just crafting semi-organic weapons and armour powered by monsters' innate abilities. Obviously, granting actual monster abilities would be a nightmare to balance, so for the intents and purposes I'm thinking here it's mostly just a cosmetic thing without further development (and I suppose the bit about causing your inventions to explode would be a bit unfitting) but one can dream...
The morphing weapons are also really MH-styled too! They're really cool.
That level four feat, I'll just need to ask a GM if instead of changing a weapon I can combine two.