Well, I have been trying to complete my shiny Dialga hunt on my US version so that I can obtain the HA Alola starters and MM them sometime soon. Of course, I do already have shiny flawless EV trained level 100 versions of them without their HA's, but I would prefer to have them with their HA's.
Anyways, I have spent much of the past few days SR'ing on my US for Dialga. Earlier today, I felt like doing some more, so I inserted my X version into my older 3DS and went to the Friend Safari. I considered trying for some shinies that I would actually use, so I went through some steps to obtain a Modest Synchronize Pokémon for the FS hunting.
So, what did I find so far today? A shiny Magmar from my X version FS. I was hoping for a shiny Larvesta, even though I already have a 5IV perfect shiny Volcarona. It would be nice to have a shiny high IV Volcarona that I obtained myself (the one I have now I received as a level 1 Larvesta through a trade), so I went with a FS that had Larvestas (I know I can use Bottle Caps in Generation VII for IVs).
For the shiny Magmar I found, Modest Synchronize did work, and he has 31 IVs in Defense and Special Attack. I plan on seeing what I may be able to do with this guy, including seeing if I feel like training him soon.
Good luck to everyone else on their shinies!
EDIT: Woo. I just caught a shiny Larvesta from that same Friend Safari. Once again, Modest Synchronize worked, and she has 31 IVs in Special Attack and Special Defense. I do not care that it apparently has a low Attack IV, seeing as it is, well, a Larvesta. I plan on thinking about transferring her to my Generation VII games and possibly training her.
EDIT 2: Well, I finally caught that shiny Dialga. After over 40 Ultra Balls and most of my team fainting, I had to use one of my Master Balls. Modest Synchronize did not work, and it is Rash instead. Oh well.
I now have three shiny Dialgas, two which I caught myself (AS and US versions). I can now see what else I want to do, such as collecting and doing some MM'ing for the HA Alola starters and possibly training some of these other new shinies.
EDIT 3: Um...ok then? I just hatched a shiny Litten during my process of getting a 5IV perfect (or 6IV flawless) Adamant HA Litten. First of all, I checked, and this guy has Blaze and not Intimidate. I suppose I will keep going through this process then. I am not even at the 5 or 6 IV HA Litten yet. This shiny Litten has an IV spread of 31/x/(30)/31/31/31. If only he had Intimidate...I have plenty of Bottle Caps.
EDIT 4: What the...I just hatched another shiny Litten. This one was immediately after my only 5IV perfect HA Litten. I hatched two shiny Littens in the time it took to get my next step in my preparation process for hatching a shiny, high IV, HA Litten. Anyways...This guy DOES HAVE Intimidate. WOO? Time to go check his IVs. (This is hilarious...) Ok, his IV spread is x/31/(30)/31/31/31. Definitely useable. I will probably train this guy sometime soon.
Well, now that I have a useable shiny HA Litten (BEFORE even reaching the expected point of starting the MM hunt), I can move on to the other two HA Alola starters I suppose. Woo.