Two Legendary Pokémon are coming to Pokémon Ultra Sun and Ultra Moon in March. Heatran and Regigigas will be available to all players in Pokémon Sun and Moon and Pokémon Ultra Sun and Moon.
These two Legendary Pokémon will be available via a code distributed in the Pokémon Trainer Club newsletter. To get the newsletter, players will need to sign up for the Trainer Club. You can do so at this page. You’ll also need to opt-in to emails by March 1st to receive the code for Heatran and Regigigas.
For Sun and Moon players it sounds like these two will be worth signing up for. Regigigas has a unique special ability that allows it force players to wait five turns with the “Slow Start” ability. Whereas Heatran is used in more typical battles. Heatran has an ability called Flash Fire which raises the power of Fire-type moves when it gets hit by a Fire-type attack.
You can check out the developers of Pokémon Sun and Moon discussing Regigigas and Heatran in the trailer below: