It isn't idiomatic, except in some unknown context.
Everybody needs somebody who can help them despite difficulties in their personality.
Many people these days seem to want to refer to persons as "that" instead of "who". It's probably a habit that has been around for a long time but it sounds much better with the more personal "who". (I know a lot of people, sometimes including myself, who suffer from DPD, Difficult Personality Disorder. It has reached almost epidemic proportions. )