Empire From Tomorrow

A modern-day chemical PhD finds himself in ancient times as the reckless nobleman. Using his knowledge from the future, he creates weapons, builds an empire, and leads his people to prosperity. Along the way, he defeats invaders and discovers love, achieving success in both his career and heart.

DramaWave released it as 101 bite-size episodes mixing romance, made to watch on a phone in one sitting or a few.

Watch it for the push and pull between two leads who shouldn't work but do.

At roughly 2–4 hours in total, it's quicker to finish than most full-length series.

Start from episode 1 below; autoplay takes you to the next episode when one ends, and nothing needs a sign-up.