You can get his 1st heart, also Othra's 1st heart, during celebration event in Lizard's treasure event. Anyway, if you missed it, you can still get their 1st heart by talking to Othra.
How can you get Roushk and Othra first heart if you miss them during the celebration event?
There would be new conversation if you go talk to Othra after you missed their hearts
Thank you! I'll check it!