Sadly no pictures because quality reasons
Well, I've encountered a total of 3 hackers on online matches. These were the hacks they did:
1.) Changing everyone's Mov to 20. I don't even think it is possible to get over 11, let alone 20! The thing that really made me surrender was the warp skill that EVERYONE had. It basically made it so they could move wherever they wanted in a short amount of time. They also had replicate but that's different.
2.) Takumi with Point Blank. I don't know if it is DLC in Japan but I know it is impossible to get in America at the moment.
3.) All Stats at 70 without pairing or skills. Most of the skills that their units had were the skills that can be activated or aren't active at the start of the game. These type of units are basically invisible. It is possible to get a hit or two on them but that is mainly it.
Post some of the hackers you have encountered and/or the ones to look out for. Thankfully there is no punishment in online battles but it is very annoying to see someone just hack there way through battles. Here's some pictures of Fates Hackers that I found on the internet. Thank you!