When I activate this Tamer's [Main] effect and do not digivolve into [EmperorGreymon], can I instead digivolve into some other level 6 Digimon, like [AncientGreymon]?
Show ruling
No. With this Tamer's [Main] effect, you cannot digivolve into any other Digimon than [EmperorGreymon].
Source: BT7-085 Takuya Kanbara