3.P template stacking

[geekintheground]

so i know pathfinder isnt really designed to handle a lot of template stacking, and there isnt RAW for 3.P, but im having some trouble with a ruling, and am looking for some help.

One of my players wants to be a necropolitan (3.5)unseelie fey (3.5) undine (PF) shade (3.5). he's using the undine's "mostly human" alternate racial trait to qualify, saying it just says he's treated as humanoid for all purposes.

im thinking that unseelie fey is an inherited template, so it would be applied first and modify that humanoid to fey, therefore disqualifying from necropolitan and shade. but he counters by saying his alternate racial says he's treated as humanoid, he doesnt actually CHANGE to humanoid, so no matter what he ACTUALLY becomes, he can do humanoid things.

(another player kinda found a way around this with the mumia from ghostwalk, and im surprised i havent really heard it talked about. it seems really solid, like, on the level of necropolitan. is there something im missing?)

[Remuko]

A few undines have appearances much closer to those of their human ancestors; in fact, they may not even realize their true race. Such geniekin appear to be human, save perhaps minor features like unusual eye color, and they count as humanoid (human) as well as outsider (native) for all purposes

Yeah that sounds like it works to me. As long as they have this trait they always count as humanoid as well as outsider "for all purposes". So I'd think that would stay true regardless of actual type changes.

[Silva Stormrage]

Ya that does seem to work, similar to using Humanoid Heritage in 3.5

Mumia however, does not work. Ghostwalk was 3.0 I believe so it doesn't have a LA tag because LA doesn't exist at that point.

If you look at the 3.5 update the example statblock for the Medusa Mumia gives LA: -. Meaning it is not playable for PC's.