According to the set bonus's description: "Final blows while your super is active refund Super energy when it ends" According to the destiny 2 data compendium: 6 kills during your super (super bar is yellow and actively draining i.e. final blows during Spectral Blades) and/or 6 kills with lingering super damage not during your super (super bar is grey and actively charging, i.e. final blows from Gathering Storm's lingering aoe) will refund you ~33% of your bar after the super ends/while any lingering effects are still active. Tested in the field in Grasp of Avarice with and without Orpheus Rig: - Super isn't refunded upon expiration after 1-6 final blows with the first two and/or all volleys from Mobius Quiver. This outcome doesn't change whether the super bar is allowed to fully drain, or the final volley is fired. - Super isn't refunded upon expiration after 1-6+ weapons final blows while the super bar is still yellow and draining. This outcome doesn't change whether the super bar is allowed to fully drain, or the final volley is fired. Note: Deadfall was not included in this test as, other than potentially killing with the initial arrow, any final blows within the influence of Deadfall are coded as weapon/grenade/melee/ability final blows, [b]not[/b] super final blows. I will also add that in mobius quiver's own description, it says: "While your super is [b]active[/b], dealing [any] damage increases the damage of your void arrows and bow weapons" So with this we know that while the yellow bar is draining, you are considered under the "active super" state.