Your design was definitely one to stand out of the crowd, there aren't many mantises in the pokéworld and they could always use reinforcements. Its use of its four arms along with its pink hide particularly draws out the psychic aspect of the design, and it fitted all abilities except Weak Armor gallantly. But for me, the excessive use of garments and symbols made its appearance unfit in the long run, namely the necklace, the swirls on the skirt, and the orb which just happens to float there.
But even though I can objectively tell why it didn't make it to the finals, it'd be a crying shame if this design wouldn't see any use, be it with this set of types and abilities or otherwise. I really like it.