There are many literary devices in the story.
First, there is personification. For instance, nature has a life of its own, and she is powerful. In fact, it is nature that pins them down underneath a tree where they have to face each other for a protracted period of time. Here is what the text says:
And before the moment of hesitation had given way to action, a deed of Nature’s own violence overwhelmed them both.
There is another personification of nature. The wind screeches as both men lay on the ground. Here is the text:
Ulrich was silent for a few minutes and lay listening to the weary screeching of the wind.
In terms of foreshadowing, there is a storm. This is usually a sign that something ominous will take place. It does, as the storm fells a tree, which pins both men down.
There is also the use of irony. The Ulrich does not think he will meet Georg, but as he move around a tree, he is right there. The greater irony is that while both men are trying to survive under a tree, they actually reconcile; now they seek to outdo one another in generosity and kindness. The final twist of irony is that the story ends with wolves coming. One would think that something good would happen after their reconciliation, but it is just the opposite.
Clearly as #2 points out, the foreshadowing occurs in the way that nature is described and the violence of the storm, the wind and the trees themselves. This indicates obviously that something important is going to happen, and as we read we note such details and our suspense rises as we wait to see how the story will unfold.
One of the best examples of foreshadowing in the Saki shortstory "The Interlopers" is when the story talks about both men wishing for the other's death. The ironic cosmis resolution to this wish is that nature fulfilled it. Both men got (or we can conclude) were going to get exactly what they had wished for-and nature was going to give it to them.
Here are some examples of figurative language:
METAPHOR - "...as boys they had thirsted for one another's blood,"
"this wind-scourged winter night"
"...the idiotic chattering laugh of a man unstrung with hideous fear"
SIMILE - "The roebuck, ...were running like driven things tonight...."
"...and he looked across with something like a throb of pity to where his enemy lay...."
"We have quarreled like devils...."
PERSONIFICATION - "the whistling and skirling of the wind
There is clear foreshadowing in several ways. The one I always appreciate the most is nature's hints. In literature, a storm is always symbolic of trouble to come. Another nature moment of foreshadowing is the fact that even the animals who were usually out at night were scurrying for cover on this night--a sure sign trouble is ahead. One of the men vows he will either kill his enemy if he finds him, or he won't come back at all. This all adds up to the pretty obvious conclusion that there will be trouble, and maybe even death. What is unexpected, really, is the wolves. They are the great irony, of course--a contrast between what is expected and what happens. Just when the two enemies become friends and we anticipate a dramatic change for the better in their lives...wolves. What a great twist!
There are many examples of figurative language. You can find personification in "and this wind-scourged winter night Ulrich had banded together his foresters to watch the dark forest." You can find metaphors in "Relief at being alive and exasperation at his captive plight brought a strange medley of pious thank-offerings and sharp curses to Ulrich's lips." (It isn't really a medley, right?) You can find non-literal language: "Good," snarled Georg, "good." (He doesn't really snarl.) You can find hyperbole: "How the whole region would stare and gabble if we rode into the market-square together."