How would I punctuate the following sentence:
Furious, John strove to catch Jim by the shirt so that he might throw him against the wall, but once more, Jim was too quick.
Where I'm getting stuck is on whether or not I need a comma before the "but once more" part of the sentence.
I have a similar issue on another sentence that is fairly complex:
When they broke apart, the old warrior bled from many wounds, and for the first time in decades, there was something close to worry in his eyes.
Here, my issue is whether I need a comma before "and for the first time in decades" or if I should leave it out.