>>44650700Keep it as only have Hidden Power, but give it an ability that raises its stats by 50% for every other Unown in the party. Having a team full of Unown would be dumb, but they'd be strong.
That or give it a Schooling variation where it summons a bunch of Unown to pile together, giving it beyond Legendary stats, but still only the use of one move. And if Hidden Power doesn't return on its normal form, introduce it as a "new" move that has a different type or effect based on the letter of Unown that has it. Like The first seventeen Unown get a HP that's of every different type other than Normal, then one has just a super powerful typeless Unown, then one that will always confuse, always paralyze, etc. It'd be a fun gimmick and a reason for there's to be 26 (+2 bonus) Unown variations.