Not all bugs are bad.
I once vanquished a Sister and then within the same session spawned a new Lich. Again in the same session we had our first encounter. I had left the same Requiem Mods on the Parazon as for the Sister and Blam. Blam. Blam. the Lich was sent to Saturn.
It surely shouldn’t have worked that way by design, and was too coincidental to have happened by chance. I haven’t yet got round to trying to replicate this awesome bug.