Sylas taking Ryze ult interaction confirms Ryzes scroll magic ?

When Sylas steals Ryze's ult he proclaims "Let's see whats on that scroll" then proceeds to use Ryzes nifty teleport.

Does this confirm what Ryze is carrying is some sort of gateway/teleportation scroll if so where to. Since Ryzes protects his scroll so diligently I'm left thinking perhaps its a gate way to the void or could be used to traverse creature from there into Runterra in mass .

or am I just over thinking some throw away dialog [sg-lux-2]