Bayonetta (SSBU)/Up tilt
Bayonetta performs an upwards pistol whip. Although it comes relatively slow at frame 9, it is a great anti-air that doubles as a combo starter, capable of leading into up aerial, neutral aerial, and Witch Twist at low to mid percents and even into itself against heavyweights at low percents. It can also hit below platforms and shield-pressure opponents from above, potentially starting a combo.
However at higher percents it loses all its combo potential, serving then exclusively as an anti-air, and its knockback growth is too low to score a KO until unreasonably high percents. It is also noteworthy that, at high percents and/or depending on positioning and hurtbox shifting, the first hit may fail to connect to the second hit against grounded opponents.