Hi,
Could you check this sentence of mine for mistakes, please?
He blacked out in the middle of a fight and no sooner did he come to than there was no enemy in evidence.
(The bold part is supposed to mean that when he came to there was no enemy in sight, but I'm not sure that it makes any sense and that it conveys the intended meaning)
No sooner did he come to than . . . . requires some kind of event that happens almost immediately after he comes to,
eg He blacked out in the middle of a fight and no sooner did he come to than he blacked out for the second time.
In your example, I'd simply say as you yourself suggest -
He blacked out in the middle of a fight and when he came to there was no enemy in evidence.
Best wishes, Clive