Welcome to Smogon! Take a moment to read the Introduction to Smogon for a run-down on everything Smogon, and make sure you take some time to read the global rules.
Deoxys-R: It loses 25% hp from Stealth Rock, is 4x weak to ice, 2x weak to Dark, Dragon, and Ghost, has a BST of 700 and is the stuff of my nightmares :o