Unown evolution idea:

Method: have 1 of every type of Unown in a box seperate from other Pokémon, they merge into one with the result having the most abundant nature (random if equal numbers among them), a level averaged from the components, and being shiny if any Unown was shiny.

Ability: Multi Power - can know four hidden powers of different types; can’t be negated, changed or swapped

BST:
Hp: 88
Atk: 72
Def: 68
SpA: 172
SpD: 68
Speed: 88

Notes:
-Swiss army knife type coverage
-Learns hidden power much like smeargle does sketch
-has a massive SpA stat to make up for reliance on 60 power moves