Same female Lead
Elements of fantasy
Political drama
Some comedy but is a melodrama
Writing is better in my opinion

-they seem to have the same director
-FL in both seems innocent but goes through a LOT OF PAIN leading to ENORMOUS character growth
-ML in both is good looking....personalities are different
(comparison is based off of novel Pillow Book and drama ashes of love)
Differences:
-Ashes of Love seemed to have a love triangle/reverse harem at some point
-Pillow Book, only the ML loves FL

The King's mother in the king' woman (so dowager empress) is the main lead in Hao Lan
In a way, the king's woman is a sequel to Hao Lan

I have no idea why these are two similar, only that everyone who adored Ming Lan reports that it is by the same director/writer and is just a great plot and extremely well written. I will return to edit this after seeing Battle.

I mace this rec because both characters have to cross a lot of barriers because of their birth.
Both must face obstacles related to others with power trying to bring them down.
They hide in plain sight, in their own way, from enemies but the manner and method is different.
Both are intelligent but overlooked.
Both experienced loss that impact the choices they make.
The similarity ends there. I think Dong Yi is more dramatic (and it is subtle for a Kdrama) and this show is much more subtle and as grounded in reality as a period piece can be. Dong Yi is after all a palace drama. This drama is not campy at all. There is no fluff, in my opinion. No filler.

-Bad CGI
-Fantasy
-beautiful costumes
-Tragedy
-Character growth
-Action
-Everyone is Beautiful
-Demon Goddess = Supremely Awesome
-Similar character archetypes
-weak to strong

The Lead has a similar personality to the lead in Cuo Dian Yuan Yang and even looks a little like him.

Male lead also falls in love first/is about 20 episodes b4 they get married, I think

The female lead in Lan Ling has a similar personality to the female lead in in Cuo Dian Yuan Yang

The relationship between the two leads is similar and evokes similar feelings from the viewer, I think, albeit a bit more passionate is Lan Ling

Differences:
There is more plotting/intrigue
There is more melodrama (I cried my eyes out in the last 10-15 episodes)
There is more violence
The female lead in Lan Ling is a little less perfect in terms of accomplishments
The male leads 'vision/dream' conflicts with his love a little while I think the male lead in Cuo Dian Yuan is more likely to throw everything away for his lover

Same actress/magic but I personally think it is better than The Legend of Zu as main character/actress is in EVERY episode with the emphasis on her experience/journey/love