West
The west radical and the west kanji are the same. Isn't that nice?
Make sure you know all those radicals, will make your life more pleasant.
せい, さい
にし
None
People are attacking from the West, so you pull out your saber (せい) and beat them back. You keep pushing further and further West until you reach the ocean and there's nowhere left for them to run.
Picture yourself fighting your way West, your saber shining in the light of the sun as it sets in front of you. You'll protect your home from the West if it takes everything you and your saber have left!