Watching AndersonBrazil’s
recent YouTube video (much appreciated, by the way!!), I realized I should certainly have given more details about how Synch’s powers work in-game, since it’s a hero with such peculiar mechanics. So let’s get into it—but first, one note about his master sounds file:
While making this mod I noticed it wouldn’t be necessary to create a master sounds file containing all of the sounds of the powers Synch would copy from other heroes, mainly because I can simply use the respective power sound of the hero he’s syncing with directly from that hero’s own master file. All it takes is that hero being part of Synch’s team, and the file access is granted. So that’s basically what I meant when I said I haven’t tested Synch with other heroes’ boosters—I just don’t know if the powers sounds I'm borrowing from their master sounds files are the same as the one I used from the OCP version. If they are indeed still there, then Synch should play their sounds normally (meanwhile, he’s got all of the effects and effects textures from these heroes’ powers in his own folder). It’s weird that Iceman’s powers haven’t showed up in Anderson’s video—while on my computer they seem just fine. (I would appreciate if anyone could confirm if there’s an actual bug.)
Ok, now regarding his powers mechanics. There are 3 powers (2 offensive and 1 passive) and one xtreme available. All of the 3 powers can point to a fellow hero from Synch’s current team--that's why he ends up having nine powers and one xtreme.
Keep in mind that Ref1, Ref 2 and Ref3 stand for each spot on the team, as shown on the main image from the release post.
The two offensive powers directly synch with the respective hero and make him attack. So, if Synch's player 1 (1st spot) and you press the 1st Attack Power (Ref1) while Cyclops occupies your team's 2nd spot, Synch'll get his powers and attack.

If Jean Grey's occupying your team's 3rd spot while Synch is on the 1st spot, you'll have to press his 1st Attack Power (Ref2) instead in order to access her telekinesis.

And so, if Iceman is on the 4th spot and you want to borrow his power to attack, you'll have to press Synch's 1st Attack Power (Ref3). (For now, for that effect to display correctly, please turn off the Fullscreen Effects option at the Video Controls game menu.)

Synch's "1st Attack Power" will always be "more narrow"...
... while the 2nd Attack Power will always be a radial attack (unless it makes no sense for that hero's power).
Now for the boost power. You only need to press it once for the hero you want to copy boost powers from, and they'll stick to you until you activate some other hero's boost power. If you have enough energy, this is the animation that will be played:

And what would those boost powers be exactly? They will basically let him use "secondary" powers from fellow heroes. Sadly for Synch, Cyclops' mutant power can't give him any of that--but his other teammates from the X-Men first class have more to offer. If you synch with Jean and Angel, for instance, Synch will be able to fly
at your third jump.
If you synch with Beast, the third jump will be exactly that (an extra jump). You'll also acquire the Mighty ability.

If you synch with Iceman, Synch will be able to slide on ice on the third jump (you must keep the jump button pressed).

Synching with Jean and Iceman will also give you a brief special effect when you press block (while it doesn't last long and doesn't change anything really, it was a nice touch I didn't want to miss).
I hope that was helpful and clear for those who got reading this far. Luckily I haven't left anything out this time.
