>>34323085I can confirm Rowlet is by far the worst option. My Decidueye only made it to the very end without dying because I rarely used him in important battles and he was the only one on my team I didn't use during the League. Then again, I didn't really need Ghost as I had two Dark types by the end, and Dark in USUM is extremely common. The only major battles it participated in were Lusamine and Hapu.
Playing on Set mode also makes Decidueye really hard to use as it's got cripplingly common weaknesses and is both slow and not bulky. Get it in and it can do work but it's hard doing that in the first place. 95% of the time I just decided to switch in one of my bulkier members, which was all of them.