Sorry for always posting walls, guys…I swear I don’t realize how long the post is until after I finish. Hope this helps, at least.
X23(AS or CS)/RR(Log)/Ammy(CS): RR/Ammy is an incredible shell for pretty much any mobile character in the game. Check out NeoRussell for some of the synergy there. I feel like the same kind of shenanigans should exist with RR and repulsor blast, I just don’t have the setups down yet. I probably would have went to this if I knew how to be anything but absolute garbage with Ammy. There’s great DHC synergy on these two and X23 gets a lot from both of them except for maybe super great 1 meter DHCs. (Though I think not having access to infinites limits the eventual lifespan on this team, though it makes up for it with some great setups.)
X23(OTG)/IM(RB)/Sent(Drones): Historically, IM has had the most success with Drones (a la Joker and Alucard), but I feel like it’s not necessarily the greatest way to play him since you’re kind of going against his strengths going with that option. I feel like if you don’t just want him to be an assist character or a low tier version of magneto you need to find a way to be able to consistently convert off his spacing game which is why I stuck with log. I don’t know what other assists offer that since I got lucky with that pairing early on. Drones works because it allows you to maintain corner pressure where you can always combo off RBs and lets you play with IMs hi/low game but you have to get on RayRay or Infrit’s level with Sent to make it really scary.
Hulk(gamma wave)/X23(AS)/IM(RB): I would count this as a broken end game team. It has so many sick setups, just check out the match I posted against Wandles. Hulk has 1mil+ combos off everything except his ground throws and even then you can still pop XF if you want to kill off that (that’s TODs on most of the cast from hi/lows/air throws/command throws/mixups/super armor moves it’s probably about as much synergy as you can squeeze out of hulk). Plus Hulks start of match with RB is rediculously strong. You get to do some really swag looking combos and even crossup setups too, which is wierd for hulk. X23 can get max damge with 2 relaunches and two of the strongest DHCs in the game with Hulk and IM. Plus you have reliable access to the 1-touch kill gimmick since you can reliably TAC through to IM from both X23 or Hulk on point. Only weakness seems to be getting HBD’d during the startup of RB or just not being able to protect IM against random supers in some situations (usually gamma crush keeps that from being too much of a problem, tho.) Gamma Wave is surprisingly good for X23 aside from the slowish startup. It lets you do some real ninja shit with her in neutral since it completely hides her in the rocks at ground level, plus works perfectly for extensions.
X23(CS)/Wesker(LowTG)/IM(RB) or RR(Log): Neither IM nor RR really need or get a ton off OTGs since places where they can extend with it they can get it themselves. But Wesker might get some extensions/mixups/resets off RB or teleports+Log(though no infinites), so you might be able to make X23/Wesker/IM or RR work, X23 would get max damage, but you might want to put IM second for the stronger DHC and do some DHC/Tag/Alpha counter to get Wesker in later, phantom dance is that real booty DHC. (Though both RB and Log pull them out of the corner when extending so it might be better than usual since it wouldn’t be in the corner.) Wesker plus Log would be some pretty broken shit, though you’d have to build combos around not having the wall bounce. Should work fine, I just don’t know enough about his upper-level mechanics.
RR(Log)/X23(CS or AS)/Haggar(Lariat) or Spencer(Armor Piercer or Slant Shot): If you want to go with other off the wall options, there’s a few characters with Hard Tag combos with RR, I think Spencer (not 100% on this one, but I’m pretty sure the tech is there) and Haggar are the notable options. RR/X23/Haggar would probably be a pretty fun team that should TOD, though I think RR would need a better neutral assist to be terrifying, but it wouldn’t surprise me if this pairing has some great setups/gimmicks. (That being said, FR_RoachKing still does a ton of work with just Wesker/Haggar/Phoenix with a lot of resets so maybe you could make it work without a netural assist. He does have the gimmick backing him up though, so…shrug) RR with restand might actually be pretty broken since you would have access to late combo net traps and X23 can hard tag and combo (not 100% if you can do that fast enough after calling Spencer, though.) Even without the X23 hard tag, the oki from this team should be hella scary once you work out the setups. You get the Jacobs Wire reset loops with X23+slant shot but I don’t know how I feel about that personally and I’m not sure if you can even use Armor piercer and it def. wouldn’t be a great neutral assist so it might be better to play that team X23/RR/Spencer. (Plus Spencer has an infinite, tho it’s not one of the practical options, lol.)
X23(CS)/IM(RB)/RR(Log): I feel like this is one of the real end game X23 teams since it also has synergy outside of the 1-touch win gimmick. Once you have consistent infinites, If you play anybody that doesn’t have an Akuma/Strider/RR (low health means you can’t build the extra meter post-dirt nap without another TAC) in their 2nd position, you can build the meter you need to double dirt nap and kill a whole team off 1 touch. Both assists work great for X23s neutral and she can extend in any order and off any starter for max damage. The thing that I really love is that it doesn’t sacrifice synergy anywhere for one of the strongest gimmicks in the game. IM and RR might not be top tier, though japan disagrees about RR, but I can say 100% that IM+log is great once you learn the spacing and I’m only on my theory game as far as how good RR+RB SHOULD be (my RR isn’t even at 50% yet, but I still feel really good about the pairing). The only thing you sacrifice on this team is not having a great XF3 derp comeback character, which doesn’t bother me that much anyways since you should always have the option to guard cancel and both characters can handle HBDs well enough to stage a comeback against people with bad pressure habits. The only bad thing about RB is that it’s a set number of hits, so you can’t use it for HBDs (at least not in a combo I’ve found that can still kill both characters if they’re high health.) That’s a pretty piddly thing for what this team offers, though. Log still works fine on HBDs (tho I’ve seen RR drop out of it before, go figure.)