By attaching an engine and throtle to your sword you have created a sword that as a bonus action you can turn burning red by overclocking the engine. By reving the engine you warm up your blade to 350°C, (this lasts for two minutes) giving you +1 to your damage as well as 2d8 fire damage. But using this feature too much (more than twice within 24 hours) might cause your blade to warp and bend, (If used twice or more within 24 hours the DM will roll a D20 and on a 9 or lower the blade will warp) making it useles in combat, you wll have to make a smiths tool check out of combat and take one and a half hours to fix your blade. The engine also has a chance of breaking if used more than twice a day, (the DM will roll a D20 if used more than twice within 24 hours, if you yourself is the person who created the wepon the DM shall add your proficency bonus to the roll, on a roll of 10 or less the engine will break) if the engine breaks you will have to suceed a tinkers tool check and take one entire day repaing it.

Proficiency with a Longsword allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Bonus: Magic, Damage, Combat, Versatile, Sap