Delibird
Preferred abilities: All 3 are good, depend of your set !
Note: Delibird is a good suicide lead with spikes, rapid spin and counter/destiny bondn Icy Wind is also a good move to lower the speed your opponent and break sash !
Other set: Hustle, Adamant nature, with Choice Band, It has good matchup vs lando, tornadus and Garchomp, since it has access to ice shard that ko Landorus impish after -1 atk and is OHKO after rocks if not intimidated, OHKO offensive Garchomp with Ice Shard, and OHKO tank chomp with Ice Punch, Tornadus cant switch it.
Brick Break is a really good move since it ko any Tyranitar, (has a 43% chance to ko relaxed Tyranitar, and is a OHKO after rocks)
As last move u can use Drill Peck if your team is weak to Venusaur, but can also use Gunk Shot if u are weak to Clefable, or Destiny Bond