Fifth is cursed by his name. It is not common for Nebayans to name direct descendants after themselves, and it is especially rare to keep a name alive for five consecutive generations.
It was likely just coincidence that Deleyr I named his son after himself. Unfortunately, the First married his daughter to a member of House Tezeta. House Cavriis claims that the Hag became single-mindedly focused on killing any with the name Deleyr Cavriis and that House Tezeta took up the banner after death. Deleyrs I-IV have all died young and under somewhat suspicious circumstances, as have a few cousins with derivative names.
Deleyr V (known simply as "Fifth" to most of his peers) is the current generation to bear his name. He is prone to reclusiveness and driven by paranoia, drink, and neuroticism when unable to do so. This makes him incredibly unpopular at parties.
Fifth was not afforded the luxury of an education through the Floating Palace's Scholar's Tower due to ReCo's takeover of House Cavriis earlier in the post-Moonbreak period, but he is still considered a genius in the field of ancient mechanics. Many Tezetans believe the tragedy of the Magnanimity of Yp Dihoc was a Cavriis conspiracy--perhaps at the orders of ReCo agents, but no doubt gleefully undertaken by V and his father, who died during or shortly before the Battle of Abarra.
He and Nihn Osada became fast and very close friends after the Battle of Abarra. They see a lot of their struggles in each other.