Hybrid Path

The Hybrid path is a combination of the Science/Tech path and the Magic path. Following this path results in a different ending. The Hybrid Path allows you to turn a Mecha Wyrm into a Mecha Dragon. You will also meet a new NPC and the final boss fight can be avoided. It is the True Ending of Aground which brings peace between the humans and Them.

Conditions

The Hybrid Path can be started by doing the Science Path first up until building the Mecha Wyrm at the Mirrow's lab. You need to evolve the Mecha Wyrm with a Evolution Gem you are able to make after defeating the Old One. Show it to the Alchemist, then make the Sub Pen with the Mirrows. Talk to them to bring the Alchemist to their lab.

If you did the previous steps right, then the first wave of the Bombardment will be delayed until you built a Bombardment Shield. Do not speak to the Elder Dragon a second time until you've built the Bombardment Shield because it will trigger the Bombardment.

Even if you did mess up the steps and get bombarded, you can still get the Hybrid Path Ending. Any crafting recipe you missed would still be obtainable this way.

You will have to finish the quests for the Scavenger, build the Mobile Lab, and research the Alien Locator for part of the Hybrid Path ending quest.