The best "Mega" packs utilize advanced video codecs like H.264 (AVC) or the newer H.265 (HEVC).
The quest for the perfect 1080p version of Kai has given rise to a vibrant community of fan editors. Recognising that even the official Kai release had its flaws (cropped picture, some redrawn animation frames that looked jarring, and a controversial replacement of the original Kikuchi score), dedicated fans created their own "ultimate" versions. This is often what drives searches for "Mega" links, as these fan projects are distributed through filesharing.
Dragon Ball Z Kai (known as Dragon Ball Kai in Japan) is a remastered and high-definition "refreshed" version of the original Dragon Ball Z anime series, created to commemorate its 20th anniversary. It was designed to provide a more streamlined experience by adhering strictly to Akira Toriyama's original manga.
