Great Old One's Tentacles will never reflect impales from a one-shot enemy

When using the Great Old One's Tentacles, impales inflicted by a killing blow on a non-impaled enemy will never reflect damage to nearby enemies, unless The Impaler keystone is allocated. The impales will be inflicted on the enemies and will be shown on their corpses, but the mod on the Great Old One's Tentacles will never cause them to reflect damage to nearby enemies.

If The Impaler keystone is allocated and more than one non-impaled enemy is dealt a killing blow simultaneously, it is possible for The Great Old One's Tentacles to cause the inflicted impales to reflect impale damage to nearby enemies.


See also: Impaler keystone doesn't impale one-shot enemies bug report
https://www.pathofexile.com/forum/view-thread/3927744