Hahha :D Depends on what "legend" means. I'm good at doing lots of stuff related to rom hacking though, but there are also things I'm not so good at. These however are mostly hardware related stuff which is something most hackers don't play around with. Some true experts know even how to change that kind of stuff to come up with new, fancy functionalities. One example I can come up with that I couldn't do on my own is to program a totally different game out of the one you're playing by encountering some glitch that allows you to write the code of your new game to ram memory. Next you make the processor to execute the code of that from ram memory instead of the original program code of the game. This kind of functionality has been used for creating a new game inside a Blue/Red or Yellow rom. I couldn't find a video of it, but it has been uploaded to youtube.
I have done rom hacking for fun since 2008 or so and in 2010 started to learn how to play around with the rom data using a hex editor. In 2012 or so I started doing more advanced stuff and yeah... been also learning since then. I can code neat stuff using the in-game script language along with assembly, but also hack existing in-game routines and functionalities. I also work as a software developer these days and studying that in university level has also helped to become better at rom hacking as well. :)