Described as the venerable Sage King (賢王, Kenō lit. Wise King), Hayden is a wise and honorable king who values his friendship with King Fado as shown in the early chapter. After the fall of Renais, he offers Princess Eirika shelter in Frelia's capital, though she declines his offer. He gives her some soldiers, including Vanessa, Gilliam and Moulder on her quest to find Ephraim.
When the two siblings return, Hayden starts a war council to determine how they should proceed against Grado in the war. During the meeting, he is informed that their Sacred Stone has been destroyed by Caellach and Selena. Upon meeting with Myrrh, he deduces that Grado is trying to destroy the Stones. Innes goes to Jehanna, while Eirika and Ephraim go to Rausten and Grado respectively; Innes and Eirika are to warn the two nations of Grado's intentions, while Ephraim attempts to consult with Vigarde and kill him if necessary. Hayden apologizes to the Renais siblings that he cannot offer as much soldiers as he would like, but gives them some war funding for the upcoming battles, and is not seen after that.
*40% in the Japanese version
Hayden's stats will not be too shabby once he starts leveling up, though his Skill and Speed appear to be a bit low for a Ranger. However, these low stats are offset by good Luck and Constitution ratings, allowing him to avoid being weighed down by heavy weapons. His stats, in the end, are nothing special; but they are not that bad either. Chances are, in the Creature Campaign, other bow and sword users are already well-trained, but after leveling, Hayden should be up to par.
- No supports
The name 'Hayden' means 'hay valley', coming from the Old English words 'heg' meaning 'hay' and 'denu' meaning 'valley'.
- Hayden is the only character unlockable in Creature Campaign that is not killed during the main story.
- The Sacred Stones official website's description for Frelia spelled his name "Haydn".
- The "Choose Your Legends" event of Fire Emblem Heroes revealed that he was 775 out of 791, making him the lowest scoring character of the Sacred Stones portion with 30 votes.