The terms and conditions are somewhat straight forward as AirAsia’s usual T&C’s go since the redemption does not include airport taxes and related fees. Flights which are eligible for redemption are only direct long haul flights with the D7 and XJ carried code,, excluding flights to Bali, Singapore, Jeddah as well as Fly-thru routes.
Additionally, bookings need to be made at least 14 days before the departure date and no flight changes are allowed. At the same time, embargo periods are also applicable to the pass which means some flights during public holidays, school breaks, and weekends can’t be obtained via the unlimited pass. While the bulk of the the D7 and XJ flights are to East Asian countries, we can confirm via this Wiki entry that the D7 carrier code also applies to flights to Australia, New Zealand, Abu Dhabi as well as India. Some of these flights have also been confirmed by AirAsia in its announcement:
Introducing AIRASIA UNLIMITED PASS – for only RM499*, you can fly as many times as you want for one year with AirAsia X when you redeem your flights with this pass! (1/2) pic.twitter.com/mDrrUmtDXt — airasia (@airasia) February 29, 2020