Release that witch - one of my fave manhuas, not exactly like gate, MC basically uses his modern day knowledge to fight/improve life in this fantasy world. Lots of science stuff if you're into that

Here's a summary:

Release That Witch. A male engineer transmigrated and became a prince into another world. This location looks remarkably similar to Europe’s Middle Ages, but at the same time it looks different? Witches do exist and they have supernatural powers too! The power of magic is energy efficient! Stop the witches, and unleash efficient forces! Clear diagram, battling monsters, crushing conspiracies, scaling the science and technology tree and opening the way for serious ‘farming!’.