Ditto what Bullet said, this moveset is self explanatory, First, using Toxic is a good idea to get some HP outta your opponent's Pokemon and stalling, Second, using Ice Beam works well with Pokemon that are not effective against Ice types, hitting them once or twice might defeat one Pokemon, but when a Fire type or a Fighting type comes, it's time to use substitute, or roost, knowing that Fire or Fighting types pack massive damage, so I prefer giving Articuno a Focus Sash if you want to hang on..well, that's all..