User blog comment:RoznosicielCiast/Leokathya, the Breathstealer/@comment-7709681-20141107020651/@comment-6061249-20141107142553

Most likely, not every spell will hit, and to perform a full combo, much more time is required than for an average champion, making the actual damage output lower.

The purpose of walking on walls is to enforce some unique gameplay, making it less "chase and hit" styled.