Genesect

Genesect is a great Pokemon in the Doubles metagame, as it's considerable for building its team's momentum thanks to a powerful U-turn. Download can provide Genesect with offensive presence once it has switched in, but Genesect has no way to control the chances of getting the boost it requires. Genesect can be very vulnerable to attacks when running Choice Scarf, as it can make Genesect Choice-locked into a poor move that gives certain opposing Pokemon a free switch in, such as Fire-types switching into Ice Beam. While Genesect isn't too flexible, it can use items besides Choice Scarf, but they give Genesect an odd Speed tier, making it slower than positive-natured base 100 Speed Pokemon such as Mega Kangaskhan and Mega Charizard Y, and because Genesect has mediocre defenses it requires a lot of team support in order to function well. On the other hand, Choice Scarf grants Genesect the ability to outspeed and OHKO top threats, most notably Choice Scarf Landorus-T.