Mana Tempest + Murderous Intent (empowered skills are not culling)

As the title suggests.

Slotting Mana Tempest with Murderous Intent should cause skills which are empowered by Mana Tempest to cull enemies.

They do not.

Recreate:
Equip Mana Tempest (Murderous Intent)
Cast Mana Tempest
While standing in Mana Tempest, Cast (for example): Spark


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Further reading:
Murderous Intent's description:
"Supports skills that can Empower skills other than themselves, causing skills they Empower, to Cull enemies."