What is the little multi-colored icon above the mercenaries head?
According to the Diablo2 wiki Diablo II wiki, your companion, which is a rogue, is using Inner Sight and Fire/Cold Arrow only. So I guess it is the "Inner Sight" skill.
According to the Diablo2 wiki Diablo II wiki, your companion, which is a rogue, is using Inner Sight and Fire/Cold Arrow only. So I guess it is the "Inner Sight" skill.