Hak already confessed his love, so this was inevitable. Honestly though, this could shape up for a Soo-Won redemption moment, where he offers himself up to the Dragon Gods, since he has the blood of the crimson dragon flowing in his veins. Thereby allowing Yona, Hak, and the other 3 dragon warriors to leave peacefully, while also removing the crimson dragon disease from anyone else who's a descendent of the Crimson Dragon.
If not that, then please have Hak demolish these Dragon Gods, they've been treacherous far too long and they don't even honor their own oaths and rules.