While he was recovering from the fight, an adventurer came seeking to reunite the Fitzharmon family crest. The adventurer gave Johnathon an antipoison potion, curing him. He warned the adventurer of Chronozon's power and told them the secret to defeating him, that all four blast spells must be used on him at least once.
Once the Family Crest quest is complete, Johnathon can enchant a player's family gauntlets into chaos gauntlets for free, provided the gauntlets have never been enchanted before. He can also later change the gauntlets to chaos gauntlets for 25,000 coins, although players can more easily use the right-click switch option themselves for the same cost. To own all three versions simultaneously, first speak with Dimintheis about buying new steel gauntlets, then visit the other two respective brothers and pay them 1,000,000 coins each.
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At one point, before you talk to him the first time during Family Crest, his examine info reads "A well-dressed nobleman." after it changes to "A well dressed nobleman." This was later fixed to always be hyphenated.
Like his brothers, he appears to be wearing a gold necklace set with an unknown grey gem.
^Johnathon, "Family Crest", RuneScape. "Unfortunately I don't have it any more... in my attempts to slay the fiendish Chronozon, the blood demon, I lost a lot of equipment in our last battle when he bested me and forced me away from his den. He probably still has it now."