The Legend of Qin (2015)

The plot in both of these series are similar. A virtuous hero chosen to lead the Mohist sect during the Warring Era China with a quest of abating war between the neighboring nations while soliciting unification for peace.
All the while, high ranks in the king's court felt threatened by the rise of our hero movements as acts of rebelling. Thus, they accused these heroes as spies with a malicious intent to bring down their nation. So they sent orders to post rewards for their head.
Beside the plots are alike, both of these stories also have many similar characters.
The only difference in these two series is that The Legend of Quin is not about time travel.
If you enjoy A Step into the Past (2018), I recommend The Legend of Qin (2015).

More or less related to Qin's era, it's the later part of Qin's story. If you had watch The King's Woman, this Legend of Qin is like a part 2 or sequence related.

Half of the story line is based on true facts from The King's Women's story. Gong Shun Li or known as Li Ji / Li Er, had a son ( Tian Ming ) with her second disciple brother - Jing Ke before she was enforced into Qin Palace and later became the Qin Emperor Ying Zheng's women. This story is part of the continuous events happened after Qin Emperor Ying Zheng killed Jing Ke and lady Gong Shun Li, about how Jing Tian Ming and few other tribes how they rebelled & survived under the ruthless Qin enforcement. Other half of the story is just a legend and a journey of discovery of the legendary "Mo Zi" inventions.

Both series are set in the same period in Chinese history (Qin Dynasty) and features the political turmoil of that era, though both are fictional and belong to the wuxia, fantasy & adventure genre. Both have a male lead that started out innocent and carefree until circumstances forced them to mature and take on the responsibilities of the world. The romances are generally tragic but in The Legend of Qin, you'll get a happy ending or two. Good story lines.