Roselia

At first glance, many people will doubt Roselia's effectiveness in UU due to its frail physical defense, low Speed, and the existence of better Grass-types. However, if you take a closer glance at its movepool, you will find that it has a interesting variety of moves that give it its own special niche. Unlike the common Grass-types, Roselia has access to the ever-so-useful Spikes, in addition to Toxic Spikes, and the ability to absorb status with ease thanks to Natural Cure. Roselia also comes equipped with a high base 100 Special Attack, which ties with the omnipresent Venusaur. Last but not least, Roselia's usable base 80 Special Defense gives it plenty of opportunities to set up deadly entry hazards on helpless foes. As long as you abuse its niches to their fullest, Roselia can be well worth the use.