I never followed fanon or Treklit, so my my Andorians are based on "Journey to Babel" and my own imagination. My Andorians were a caste based Matriarchy. Each family/social unit is comprised of a female and groups of three males from different castes called a triad. The bond between the males is very deep and can only be broken by death. The number of triads bonded to each female varies. The Matriarchal Council that rules Andor is comprised of the most powerful females.
Slev's triad was killed and he is "bond-broken". His membership in the Warrior caste led him to Starfleet, which is one of the few places that will accept a bond broken Andorian. He thinks of April and the Chief as his triad bond brothers, even though he is no longer bonded to a matriarch. Sorry, no ice powers.
( yeah, I spent way to much time on this.)