Shadow Dancer Shadow Companion Help

[Phawksin]

Actual Question: If a Shadow Dancer character wanted to make this Shadow companion more meaningful and advance interestingly, how might you institute that? I have been looking at ways to use something like the "monstrous companion" feat, or like some kind of summoner eidolon, but its proving to be less intuitive than i would have hoped. Lets also assume that the Shadow being a shadow (and doing str damage) isn't as important as having a shadow-like companion from the shadow plane.

Non-important background information: We are playing a game set in the Scarred Lands (started long before they announced the PF re-release, and we are very excited) and we have just encountered Shadow Dancers, followers of Drendari, introducing the opportunity to gain levels in the PrC. I'm playing a really interesting (read: stupid) character that already has levels in 5 different classes. This hasn't been a problem because we are a low powered party anyway and we aren't doing a ton of combat in this game. I like the concept of the class, and I have been wanting to get a pet (because I watched Jurassic World and thought for the first time ever "I want a pet class") and the SD's shadow companion seems really cool, but its advancement is boring (though totally powerful, thats not the problem). I'm looking for a way to put a little more RP punch in the mechanics of the feature.

[Aergoth]

I haven't looked at it in a while but Ethereal Gears had a whole slew of shadow focused brew in this thread. It might be possible to adapt some of the work there to what you're looking for.