The Godspawn Helix Staff is a Hardmodesummon weapon dropped by Astrum Deus. It summons an Astral Probe that orbits the player and fires homing astral lasers that pass through tiles.
Its best modifier is Ruthless. The Mythical modifier provides the widest array of stat bonuses, but these primarily affect the initial summon rather than the resulting minion. Additionally, minions cannot deal critical hits. The only lasting advantage a Mythical Godspawn Helix Staff has over a Ruthless one is knockback.