No. The Lv.X pokemon is counted as the stage of it's previous form. For example, Mespirit Lv.X counts as a Basic Pokemon, and therefore does not affect Mewtwo Lv.X.
ya, some conditions, like this, garchomp lv.x restore torterra. then you level up that torterra. that torterra lv.x will become basic pokemon.
correct me if i wrong