If a Nihilicist became a half-succubus and took the Improved Possession feat, would it be able to possess a Kineticist and use its elements? If not, could a Kineticist under the same circumstances possess a Nihilicist without them losing the archetype? The rules on the Nihilicist are as follows.
"A nihilicist can never be forced to gain any element, kinetic blast, or wild talent. If the nihilicist ever willingly gains a primary element or any non-universal wild talent (with the exception of those associated with empty blast or zero blast), they permanently lose this archetype, becoming a normal kineticist and gaining any kineticist class features this archetype replaced."