Sylveon

Sylveon is the team's highest-power Round user: Pixilate converts Round into a Fairy-type move, and Fairy Feather stacks a further 20% boost, making a boosted 120 base power Round effectively hit at 144 base power with STAB. Quiet nature maximizes damage output from Sylveon's high 168 base Special Attack while accepting low Speed, which can actually enable it to attack after Aerodactyl in trick room or simply rely on Round's priority trigger. Even without Round, Hyper Voice provides spread Fairy damage through Pixilate, and Draining Kiss offers HP recovery. The 23 Def stat points give meaningful physical bulk to let Sylveon soak hits from faster attackers.