Something with a purple cape, white clothes and black flowing hair. I cannot find any pic since i am not familiar with this kind of search. Just a generic Byzantine noble would do 
Here is a pic which is not exactly of a general, but is close to what i have in mind:
If you want (and if you can/feel like it) you could even make a pulsar around his head, it should make the unit more unique
As for flags, there are some simpler emblems of the Byzantine empire, such as the bicephal eagle:

Here is a pic which is not exactly of a general, but is close to what i have in mind:

If you want (and if you can/feel like it) you could even make a pulsar around his head, it should make the unit more unique

As for flags, there are some simpler emblems of the Byzantine empire, such as the bicephal eagle:
