>>33419479Mewtwo just works for me. It really just embodies this concept of a reclusive pokemon of immense power that's spoken of only in whispers and rumours that next to no one has actually seen or heard of, just waiting to be discovered.
My second favorite is Xerneas, just because it feels like it so perfectly fits into nature, and it just beckons the imagination to see it wondering a forest a la Princess Mononoke, with flowers and life springing from where it's stepped.