Rain of arrows no mana behavior

This skill has no basic attack behavior.

If you don't have any mana and you attempt to attack with rain of arrows, your character will do nothing. It is expected that your character attacks with his basic attack instead.

This may not seem like much, but if you rely on leech and play maps with no mana regen, this may be as deadly as any other bug.

I've seen this answered before. It's intentional because RoA doesn't use default attack animation.