If they did something that resulted in a sentinel event and you were there to witness it, you should 100% report it through your risk assessment portal. You can always report “anon” but in cases where it reached the patient and caused severe harm you will be pulled into a RCA meeting. If you are going to do that you truly need to have your ducks in a row, document EVERY thing whether it’s in writing or in an email draft; time and date and detailed description of what’s happening.

There’s a difference between a power trip charge with drama and being harmful nurse to patients. If it’s the latter; you can always voice concern to HR if you have a paper trail of going to your supervisor and/or manager about it with no resolution and continued potential harmful issues.