All three Attack IV witches are pretty decent. The Range Up witches have some map specific utility but the Attack IV witches can actually kill things during skill activation on top of slowing, which is pretty cool. Despara in particular is easy to underestimate since she doesn't look all that special compared to Fignelia but in practice there's plenty of maps that she can neuter by cheaply parachuting in and bombing away. Basically, the damage output of 1 Belinda is OK but nothing special while the damage output of 2 Belindas for 16 UP and one less slot can be pretty hax.