EMB-505 First Officer reported receiving 'GEN 1 OFF BUS' and 'SHED BUS OFF' messages at cruise which led to cascading failures including cabin pressurization and some autoflight displays. Crew diverted and landed normally.

Narrative

A few minutes after reaching FL430 on our way from ZZZ to ZZZ1; we received GEN 1 OFF BUS" and "SHED (Shedding) BUS OFF" CAS messages. My PIC ran the QRH checklist and completed the required action items. I pulled up the electrical schematic on my right-side PFD (Primary Flight Display) and saw that GEN 1 was reading very low and was not functioning normally; if at all.As my PIC completed the procedure and it was clear the generator had not reset; I told him I would take the controls if he wanted to contact the company to discuss possible diversion options; which he agreed was a good idea. Within seconds; we lost PFD 2 and the MFD (Multi-function Flight Display); and the left seat pilot's (LP) PFD displayed a long list of warning and caution CAS messages and flags across the screen. After a few seconds of "reaction time" to assess the situation and get our bearings; the PIC motioned for me to start a descent. Around this time; it became clear we could no longer hear each other. I yelled at him to put his mask on; and after doing so; he took the controls since he was the only one able to hear ATC--my audio panel (AUDIO PNL (Panel) 2 FAIL) was among the many systems that had failed.I squawked XXXX on the LP's Garmin Touch Controller (GTC) before beginning what I felt were the most critical QRH checklists. There were pages of CAS messages to scroll through. During this time; we had to communicate by briefly removing our oxygen masks and yelling commands; checklist information; findings; what ATC was telling him; along with other pertinent details. To make matters worse; the cockpit windows fogged over completely; making it impossible to see outside during our descent. Cabin altitude was well over 20;000 feet--I'm not sure how high it ultimately got; but a photo I took of the LP PFD during our descent to capture a photo of the CAS messages - that we thought a maintenance might find helpful later - shows a cabin altitude of 21;000 feet while we were passing through FL220. The temperature change and fogged windows also caused our iPad suction mounts to fall; adding to the confusion and chaos in the cockpit as I was running checklists. I was using the paper QRH; and when the EFB mount fell; it became tangled in the oxygen line; taking a moment to free. Once I removed it; I was able to regain use of my EFB and began gathering information on ZZZ2; as it was clear--based on our position and ATC guidance--that it was our best diversion option due to proximity; runway length; and available emergency services. During our descent I noticed the airspeed and altitude indications seeming to be "twitching" would be the best way I can think to describe it; they were jumping around sporadically; granted small fluctuations but fluctuations nonetheless. This briefly made me question the accuracy of the information that they displayed. This abnormal indication subsided at some point in our descent.We transferred control several times throughout the remainder of the flight as my PIC needed to focus on specific tasks or take short break from the heavy control pressures since all trims systems had failed at cruise altitude. Upon reaching 10;000 feet; we removed our masks. The PIC requested a few delayed vectors so we could continue running checklists; verifying numbers and calculations; and assessing what systems were functional; what systems weren't; and how to mitigate potential threats during the approach and landing.I performed and completed landing distance calculations; confirming we had ample runway for our situation and landing configuration. I programmed our landing speeds for a no-flap landing and double-checked my calculations to ensure no errors. We elected to extend the gear early on an extended final to verify proper operation--even though we had no CAS indications of gear issues--since it was clear more systems were inoperative than functioning.Once we completed the most critical checklists and calculations; we requested vectors for the ILS XXL approach. We were IMC for part of the approach until breaking out below the cloud layer on final. During portions of the vectoring and most of the approach; my PIC asked me to manage the throttles to maintain target speeds due to the heavy control pressures. He resumed throttle control around a 2-3 mile final and he was stable by or before the "500 STABLE" callout.The landing was uneventful; and the brakes functioned normally; though we had briefed the use of emergency braking if necessary. Again; no CAS message indicated a brake issue; but we remained cautious given the number of failed systems. After landing; we received a "LG WOW SYS FAIL" CAS message. Taxi to FBO was uneventful.Before shutdown; we also received a "FUEL PUMP 2 FAIL" CAS message. We did not restart the batteries after shutdown. The cabin passenger oxygen masks were all hanging down. We secured the aircraft; closed all windows and put up the cockpit sunshades; we left the exterior panels unlocked for the maintenance techs per instructions from company; and we left the main cabin door unlocked but stickered."