TRACON controller in charge reported sector training was being conducted by instructor who consistently fails to follow procedures resulted in a CFTT event.

Narrative

I was working the radar CIC (Controller in Charge) position while Person A was training the sectors combined. The traffic was slow and not even remotely complex. I was watching the set from the Satellite position. Person A instructed the trainee to clear a VFR aircraft for a practice approach below the MVA. The aircraft was at 045 in the 052 MVA. I immediately said he is below the MVA. Person A then instructed the trainee to ignore me and not worry about it. By this time the aircraft was turned towards a lower MVA and I did not want a fight so I kept watching. They had gotten to the point that they were a few calls behind and data blocks were not being updated. An aircraft had asked for a practice approach into ZZZ from the ZZZ1 sector. I waited and waited watching; the trainee sent the aircraft direct to ZZZZZ. His only next step would be to clear the aircraft for the approach; so I said what frequency is the aircraft on? Person A then told me to be quiet and let him train. A few seconds later the supervisor came in the room; I asked her to take back over and relieve me from position and removed myself from the situation.Person A is a detriment to the facility and flying public. This is a very dangerous habitual offender; and he has had multiple reports from pilots; coworkers; etc. Not only did he clear an aircraft for an approach below the MVA; but he completely disregarded the CIC and TOOK NO ACTION to fix the situation. Additionally; he was training; and told a trainee to ignore the CIC and to allow the aircraft to continue cleared for the approach. This controller has zero accountability and blames others for his poor decisions. I guess if I have to make a recommendation it would be that this controller not be allowed to train; and no other controller should be put in a position to answer for someone who doesn't follow the basic rules of the JO 7110.65. I am not comfortable being CIC when this person is working.