Rotom

Rotom's fantastic typing and Levitate give it resistances to Flying, Steel, Bug, and Electric and immunities to Normal, Fighting, and Ground, letting Rotom check dangerous threats such as Archeops, Scyther, Vivillon, Tauros, and others. A Ghost typing allows Rotom to spinblock and hit the common Psychic-types super effectively with STAB Shadow Ball. Access to Volt Switch makes Rotom an excellent pivot for many different teams, and moves such as Will-O-Wisp and Trick give it the ability to cripple switch-ins, especially bulky Pokemon immune to Electric. Unfortunately, the low Base Power of most of its moves means that Rotom's power is often rather lackluster. Because of this, most Pokemon immune to Electric have little problem blocking Rotom's Volt Switch, as they can generally stomach several Shadow Balls. Rotom's susceptibility to the common Dark-types doesn't help, either. In addition, even though it sports many great resistances and immunities, Rotom simply doesn't have the bulk to make the best use of them. However, in spite of its flaws, Rotom's qualities make it one of the easiest Pokemon in the metagame to fit onto various different teams.