The first thing about the protagonist that I want to talk about is the plot of Douluo San the protagonist stayed in the pirate world for 35 years so his memory of Earth is not that strong so most of the plot of the Legend of the Dragon King will be forgotten only same details will be remembered such as the main charter is tang wulin and the heroine is named Gu Yuena the protagonist doesn't that Na'er and Gu yuena are the same person only after meeting Gu Yuena disguised as Gu Yue (Gu Yuena won't split ) will he notice and some other details.
About the romance part, the protagonist and Gu Yuena will have a partnership as they both face the same enemy of the plane master Tang Hao, and love will come with time (I'm not a fan of brainless love in most novels).
The writing style won't be invincible in the early stage but later in the middle and later stage.