Tooltip: Rallying Cry

I've summoned a Ruins Hellion (Quay) as a spectre.
Periodically, I will get the "Rallying Cry" buff icon, as expected.
The tooltip says: You deal increased damage and have increased mana regeneration.
When the buff is active, I do NOT have increased mana regeneration, at least not according to the character sheet.
Thus: Either the tooltip or the character sheet is inaccurate.
The wiki indicates that the buff grants my minions increased damage (am unable to test this) and grants reduced damage taken (which would be surprising).
Is there any way to test this?
thanks