You can get 2 hearts for Roushk and Priestess by doing bonding event with them (go talk to Priestess and choose 'Bonding'). Repeat it (I mean you can doing this event almost every day, at a certain time.) until the forth option appear to be selected.
During cerebration after finished lizard's treasure event. You can gain 1st Othra and Roushk heart from answering Othra question. And 2nd heart from bonding event. Please make sure you choose the right choice.
