>>20873302Lugia has multiscale, high speed, and due to Calm Mind it's not a push-over offensively.
Skarmory has multiple weaknesses/neutralities to common special types (electric, fire, ice, water) so it wouldn't be that great at taking special attacks from strong attackers. Even with base 140 SDef, Keldeo, Thundurus, HP Fire Greninja, Y-zard, CM Lando, Heatran, and a bunch of others would have no issue with it. Also 100 base attack is pathetic without an item.