This is probably old news, but after playing through the MSX2 version of Dragon Slayer IV: Drasle Family, I was tooling around on Japanese wikis and stuff for any tricks or cheats I may have missed, and I discovered that there's a way to skip the father's route entirely. After you've obtained one crown, you can use the son, Royas, to warp directly to the father's crown room and save a TON of time -- which is incredibly helpful, because the father's section of the dungeon is very long and VERY frustrating!
I couldn't find any videos showcasing this trick online, so I made one of my own and uploaded it to YouTube (sorry for the fuzzy, washed-out image -- I really need to invest in better capture equipment!):
https://www.youtube.com/watch?v=PRFh49ietl4
Check the video description and annotations for further details.
I figure, everything I post on here is just me asking you guys for help with something, so I might as well contribute where and how I can, even if it IS old news. ;)
I'd love to see somebody use this technique in a speedrun sometime! I imagine it could potentially knock a good 5-10 minutes off of any run, since Xemn's section is always the most time-consuming.
Hope this helps somebody!
-Tom

