tl;dr: He can redirect it back to your mage.
Reverse Attack is kinda funny in how it works.
When this creature is attacked, you must reveal Reverse Attack during the Avoid Attack Step. The Attack is avoided and then redirected back; this creature becomes the new source (although the attacker stays the same), and the original source becomes the new target (even if the original source would not normally be a legal target), for the next 2 steps (Roll Dice and Damage and Effects).
They key is that the original source becomes the new target even if it would not normally be legal. Reverse Attack makes the attacker attack itself, and ignore targeting restrictions.
Obscured, granted by Cloak of Shadows, says
Obscured (Object Trait) This object is difficult to see. It cannot be targeted from more than one zone away (this is for all purposes - ranged attacks, spells, abilities, etc.). Any enchantments or equipment attached to the object also gain the Obscured trait, but attached conjurations do not.
Cloak would normally prevent the attack from targeting from more than one zone away, but Reverse Attack doesn't care about that. The attacker is attacking itself at range 0, (even, though, technically, the source of the attack is at range 2) and in any case, Reverse Attack ignores targeting restrictions.
There's one famous example where Reverse Attack works even though the attacker is behind a wall and using Archer's Watchtower. Reverse Attack just doesn't care.