SRD Talk:Mind Seed
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Okay, hypothetical situation:
A Psionic Mind Flayer with 6 levels of Psion (Telepath), which is enough class levels to learn Mind Seed, targets a Bugbear Natural Lycanthrope (Werewolf) and the Bugbear fails their save.
Now what happens?
The Illithid Telepath has 8 Racial HD, 6 Class Levels, and an ECL of 21. Does the resulting creature have the Illithid stats it had at ECL 13? That would be into the Monster Class Levels, which brings up the question of how much of the Racial Traits transfer? Fairly, I understand the Tentacles and Extract doesn't come along, but what about the Racial Psionics which allowed the Illithid to learn Mind Seed in the first place?
What about the Bugbear Lycanthrope Racial HD and abilities? Lycanthropy is a physical affliction, so I can see the argument that the Bugbear/Illithid would still be a Lycanthrope. Then how do those Racial HD stack with the Illithid 13 Monster Class Levels?