Unown is just like Man; it dies to Pokémon with move. But for those who are unprepared for Man's—or rather, Unown's, for they are one and the same—unpredictability, they too will fall.
This is an ingenious moveset spread across the ages, constructed piece by piece with painstaking care in the arching caverns and ancient machinery of the most devious and cunning hive mind in the history of anything.
This moveset brings Unown's fullest potential into the light. His most powerful move, Hidden Power, rips through Magikarp, Hoppip, and Feebas with its unimaginable power, 2HKOing and OHKOing Magikarp and Hoppip with Hidden Power Ice, respectively. A neutral Hidden Power gives Feebas the ol' one-two-hit KO. When facing such opponents, Unown is unbeatable.
As if this wasn't proof enough of Unown's superiority, Hidden Power Ice OHKOs Flygon. Transporting to prehistoric ages, Unown can 2HKO the powerful T-rex, Tyranitar, with Hidden Power Fighting. And going even higher up on the evolutionary ladder, Groudon is 2HKOed by Hidden Power Ice.Team Options & Additional Comments >>>
There is no need to use any move but another typed Hidden Power, for its power is secret, hidden, locked away.
Checks and Counters
Anything that resists its mighty Hidden Power or has equally as mighty Special Defense beats the mighty Unown. Blissey, with her fatness stretching on for eternity, walls Unown for perpetuity, even if its Hidden Power is Fighting kung fu. Grumpig is an equally good candidate.