A321 First Officer reported electrical systems loss lead to cockpit instruments and lighting to fail. The flight crew requested priority handling and diverted to make a precautionary landing.

Narrative

Normal departure from ZZZ1-ZZZ2. Upon reaching TOC at FL330 cockpit went dark including CRTs. ISIS remained on. CRTs came back on quickly. Rest of cockpit remained dark with no backlighting. Autopilot disengaged and numerous warnings began to show up on the Electronic Centralized Aircraft Monitor (ECAM). Captain was flying and continued to fly; verbalizing his aircraft. ZZZ3 was visible off our nose in the distance. I had my flashlight stowed next to me to locate switches as I began to run through Quick Reference Checklist (QRC)/ECAM actions. Captain requested priority handling with ATC. After ECAM actions were complete the captain transferred controls to me while he went through the Quick Reference Handbook (QRH) procedures. We were able to use the dome light to illuminate the flight deck at this time. QRH procedures included starting the APU; which was done approximately 20 minutes after the onset of the event. This restored the remainder of the cockpit backlighting; Blue Hydraulic system; and autopilot. A landing assessment was completed for the landing in ZZZ3. I transferred controls back to the Captain who landed in ZZZ3 approximately 15000 lbs overweight. We were met by CFR clearing the runway to check the aircraft and waited for brake temperatures to stabilize before taxiing to the gate. Sudden loss of all lighting in the cockpit at night added to the complexity of the situation to recognize and assess the failures. Multiple failures all presented at once resulted in difficulty assessing the root of the problem. Loss of lighting in the cockpit made it difficult to work the COMMS and FCU until we were able to get the dome light on. We followed the procedures of the QRC/ECAM. There were several ECAM procedures to work through which added to the complexity of the situation. Some ECAM procedures would cause associated messages which added some confusion on determining the root cause of the problem and other system failures. Using all available resources (ATC; Dispatch; Maintenance; Flight Attendants; CFR) helped greatly in the situation and I don't have any suggestions on how they could have helped better. As a new hire First Officer I believe my training in the sim helped immensely to deal with the situation. Multiple ECAM warnings and procedures would have been extremely difficult to follow without the ECAM Methodology taught in the training center. This allowed me to move through the ECAM procedures and assist the Captain with task loading as we cleared through each warning message. I implemented the FIX strategy constantly throughout the flight and it helped me stay up to speed with everything that was happening as well as knowing who was always flying the aircraft. Although new to the Company and the Airbus; I felt I was adequately prepared in my training to be able to assist the Captain throughout the event.