[Sorcery] Super Mount Ally Question
 

A sorcerer in my game is looking to create an insubstantial mount that he can ride, mainly as a replacement for a physical mount that needs to be fed on long trips. We made it up as an ally and everything seemed good. A problem arose when we were thinking about the same idea scaled up, a mount that gives HUGE amounts of move, or flight, insubstantial, Force field DR, and so on. Should the rider have to buy those abilities as well with the granted by ally limitation? Should there be an additional limitation because you have to be on the mount and not just have the mount summoned?

Re: [Sorcery] Super Mount Ally Question
 

It depends on how common the protection is. A huge mount will likely not fit in a dungeon. Thus if most of the fights happen in a dungeon an additional accessibility might be in order. But if your campaign has most fights be mounted then not.

Re: [Sorcery] Super Mount Ally Question
 

Nope, just because your horse can fly doesn't mean you have to pay for Flight. Granted By Ally means you can use those abilities just because your Ally is nearby. Force Field DR will require Area Effect and Affects Others, while Insubstantial will require Can Carry Objects to affect passengers, though.

Re: [Sorcery] Super Mount Ally Question
 

Probably not. As another in this thread has stated, the Granted by familiar limitation means that the powers are conferred to you once you've made the accessibility roll for the Ally. So, if the mount merely being present confers those abilities to you, then yes, you'd take all of the relevant Abilities with the Granted by familiar limitation. However, if it's the familiar itself that has those abilities, then that just increases the point value of the Ally (and probably the point cost to you to have it as an Ally).

It gets a bit tricky if you get Insubstantial or DR as a function of riding on the mount. insubstantial specifically has the Can Carry Objects enhancement. Which, for the mount, you would be the object! So you'd just pay extra for the enhancement depending on how much extra weight as a function of its encumbrance level you'd expect to turn Insubstantial. Similarly, Damage Resistance has the Force Field enhancement that extends the DR to (among other things) "anything you are carrying". You could interpret that (again) as you being something the mount is carrying.