I suggested AC Mention, because it more reliably 2HKOs Skarmory (Adamant Nature) without a turn to set up DD. That means Dragonite can possibly Fire Blast Skarm as it switches in and Dragon Dance as it switches out, allowing it to set up without getting phazed. However, Dragonite would have a harder time dealing with Ferrothorn, although it still 2HKOs Ferro (falls short in a 3HKO when Raining, though). Fire Blast also doesn't help at all against Jirachi, so Dragonite would either have to muscle through Jirachi with +1 Outrage or have a partner to weaken it.