Make an onslaught on and Set upon

Set upon and make an onslaught on are semantically related. In some cases you can use "Set upon" instead a verb "Make an onslaught on".

Set upon verb - Assail or attack on all sides: "The zebra was beset by leopards".

Make an onslaught on and set upon are semantically related. You can use "Make an onslaught on" instead a verb "Set upon".