The main thing I'd say this hack is really useful for is for skipping rooms with tough enemies (e.g. If the Fire Golem in Kastulle Lower usually gives you problems, and this time has Increased Def and HP Restore, just kill the rest of the room and then Stage Clean). Or, in the case that Lass Kaze'aze does her little disappearing act and you can't find her, Stage Clean and move on.
Also, my favorite thing to do with this is make a little bot from Axife and Sandboxie. A quick tutorial for making a bot:
1. Open Sandboxie's options (Sandbox --> Default Box --> Sandbox Settings).
2. Go to Restrictions --> Drop Access, and make sure the box is unchecked. Then, go to Restrictions --> Hardware Access and make sure both are checked.
3. Go back to Sandboxie's main menu, then do Sandbox --> Default Box --> Run Sandboxed --> Run Any Program. Find AxMRec (Axife's main EXE) and open it with Sandbox.
4. Open hack and Grand Chase, and then record a bot like you usually would...and enjoy.
EDIT: I've been Wyrm-botting Dio since level 35. If you Full Wyrm 3-star with a bot, from level 35 to level 39, you'll get maybe a level per hour. Then it'll take a bit longer afterward. Maybe FoL will work better, but I don't know.