Responses
Think that's Silver Diamond
http://www.mangago.me/read-manga/silver_diamond/
Yesssss, thank you sooo much!
Its an isekai shounen ai/yaoi manga.
- uke was good with plant and can create them
- seme was some kind of immortal monster (I think)
- It had a lot of chapters
- The uke had a twin/doppelganger and was the prince in the other world
Thanks in advance!