I know we'll be getting official stats on the Inquisitor Lightsaber when Ghosts of Dathomir is finally released, but from the sounds of it, that might still be a while. With that in mind...
Thematically speaking, the Inquisitors in my campaign have the same style of lightsaber as what we've seen thus far in Rebels. To me, it makes sense for the Inquisitors to have more standardized lightsabers than the Jedi Order, and for their lightsabers to be more gimmicky to make up for lack of skill. Take this quote from Dave Filoni, for example, "The lightsaber for the Inquisitor is like a cheat-mode for a lightsaber. It does a lot of things that Maul could do on his own. To have a weapon that cheats those abilities and makes up for a lack of ability in some ways is very representative of who he is."
Filoni basically says that the Grand Inquisitor doesn't have the skill of Darth Maul, but that his lightsaber helps make up for that lack of skill by letting him accomplish similar things. So far, I haven't bothered properly trying to stat such a lightsaber out in my campaign. The one Inquisitor my players have faced didn't use the spinning feature of his lightsaber at all, instead opting to use it as a standard double-bladed lightsaber. I basically treated it like a Temple Guard's Saberstaff, giving it Defensive 1 on top of the typically Linked 1 given to double-bladed lightsabers. This was to account for the hand protection offered by the metal ring around the handle, which we saw protect the 5th Brother and 8th Brother from getting their hands chopped off in the Season 2 Finale (not that it saved either of their lives, but it almost did save the 8th Brother). However, even though I've already come up with a basic homerule for that one Inquisitor, I'd love to have more thorough rules for the Inquisitor's saber before season 2 of my game kicks off (since there's a real possibility of one of my players joining the Inquisitorius).
So, with the idea that the Inquisitor's Lightsaber makes up for lack of talents, how would you homerule the weapon? I'm thinking "Innate talent: Reflect 3" and Linked 3. Gives them some defensive skill, and makes up for lack of Saberswarm (Which, for what it's worth, linked and auto-fire trigger off of extra success rather than advantage in my game). To offset how powerful that might be, I'd also have it increase the difficulty of all attacks made with the weapon. Does that sound about right? For the record, I'm also most definitely not going to give it a flying feature. Helicopter sabers were over the top.
What about you guys? Have any of you tried homebrewing the weapon in question? If so, what stats did you give it? And did you add any neat perks?