There's more to doing Malygos in 5 minutes than just "stack as many sparks as you can and hope" (in fact, you explicitly do *not* want to stack as many sparks as you can.) How to do "You Don't Have An Eternity"....:
Narrated video:
http://warcraftmovies.com/movieview.php?id=98809
Written guide:
http://www.stratfu.com/strats/MalygosFiveMinute
Hopefully it's useful to someone out there.
We found it far easier when we thought about the timing and realized we didn't just want to stack as many sparks as our raid could handle, there actually is a specific number you want to stack.
Other guides:
Sartharion + 3D:
http://warcraftmovies.com/movieview.php?id=96831
Malygos:
http://warcraftmovies.com/movieview.php?id=98155
