Euryalus is one of the members of Wikipedia's 2015 Arbitration Committee who banned our editor Coat of Many Colours following a complaint by the Wikipedia editor Hafspajen that Coat was hacking Hafspajen's computer. Hafspajen later claimed that it was Wikipedia itself that was hacking her computer. The issue was investigated by Wikipedia and no evidence was found to suggest that Hafspajen's account had been compromised. Hafspajen nevertheless continued to maintain that Wikipedia was hacking her computer and ceased editing at the beginning of the year (2016).
Euryalus doesn't self-identify on his (or perhaps her) User page and we don't see him plausibly outed anywhere. His edit times and topics suggest he edits from Australia.
Edit stats conducted mid-April 2016 show that Euryalus has made some 30,000 Wikipedia edits over the last nine years. This is considerably fewer edits than most Wikipedia functionaries ratch up. He made adminship comfortably on his first attempt in 2008. Some 53% of his edits are in article space, on military history and Australia related themes especially. We are not aware that Euryalus has been singled out for any special opprobium regarding his various duties as a Wikipedia functionary.
He is one of a number of Arbitration Committee members to have resigned his membership early, on pressure of work it would seem. A Wikipediocracy thread refers. He appears to be held in high regard by both community and critics.