That can't be done in the context of this forum as the aliases are not standard so we can't suggest the user uses them. Therefore we would have to provide relatively complex commands, prone to typos either on our part or the OP.
The first thing I would do is cat /var/log/syslog then scroll back to the restart time, and in maybe 20 seconds would generally get a good idea of what happened. If you are going to have to run a number of journalctl commands to work it out then it will, I imagine, take significantly longer, and again require a number of non-standard aliases, or the use of relatively complex commands.
Also I was wondering where you would see the equivalent of syslog just stopping, often with a block of null characters on the end, which shows that everything just stopped without warning, such as you get from a PSU issue for example.
