ill know most people have said these but im just gonna throw out all the ones I know.
meterless into ultra, I only know of the 4:
focus crumple > u2
nj.hk > u2
j.hk > u2
any? jt > u2 against airborne opponents. I believe all versions of the jt cause juggle on airborne, obviously only the distance makes a difference but I have done u2 from both the hk and mk. Timing feels quite strict to me so I dont do it often, I usually just do a mk.rj or st.hk
edit: I believe on rare occasions you can trade a lk.rj in the corner and can ultra after it, however ive only done this once and cant remember the character i played… think it was dudley, I **havent **been able to replicate it!
edit 2: I just remembered, I believe you can do a counterhit hk.iajk into u2! ill do some tests in a moment and report back later. im sure someone else can confirm or whatever
ex.jk in corner > u2. - Must only the first hit, the 2nd hit alters the juggle state and to my knowledge only the 2nd hit of a lk.rj will follow up.
ex.iajk anywhere > u2 - again only the first, the 2nd has a ‘spiking’ effect.(dont know what the effect is called in sf, think codys nj.hp! or onis nj.mp!)
both the above need to be done on airborne opponents!
note: I have done an ex.jk > u2 in the middle of the field however I believe I caught the jump perfectly, you just have to judge the distance.
ex.jt in corner > u2 - dont believe this is timing specific, even better now its immune to fireballs!
ex.jt crossup > u2 - this is spacing and character specific. Usually easiest when you are in the corner and they are a certain distance back.
any rj FADC u2. Be careful in the corner as it whiffs on some of the smaller characters if you do it too fast!
I dont think you can FADC any other move of Adons and follow up with u2.
only tips I can give with doing FADC
I found it better to break it down. do a lk.rj then FADC dash, no follow up. Practice that until you have it down.
FADC’ing Adons rj is almost instant, do the motion then immediately press focus.
One thing I found when I first started was that I didnt hold down focus while I did the dash!
There are a variety of methods for this though. I believe if you finish the rj on a forward input then tap forward again when pressing the focus you should dash immediately? perhaps someone can clear that up.
Personally I press focus then tap dash twice while holding focus down. I find Adon has quite a long time to do anything after the juggle, so this method helps me with the timing.
Once you have the dash down you could even try doing a double FADC.
lk.rj FADC lk.rj FADC lk.rj.
This isnt good in a match because it burns loads of meter and doesnt do any more damage due to the way damage is split on first and 2nd hits! but I found it helped me at least.
Hope some of this helps and sorry it was so long, im rubbish at explaining things.