I have two shiny Crobats with Naughty natures, a level 1 untrained Bulbasaur with a Jolly nature, A steelix with naive nature, a luxray with serious, and a victreebell with naughty nature.
I would never keep any hacked or cloned Pokémon. So I would never trade them. In case I notice that something I got via trade is hacked or cloned I delete it.