This background for shardminds represents one aspiration that many of that created race have: to restore the Living Gate by killing the beings that keep it shattered: other shardminds.
You believe that when a shardmind dies, its animating life force returns to the site of the Living Gate, where it shores up the universe’s defenses against the Far Realm’s intrusion. Thus, you seek to kill as many shardminds as possible, starting with the adherents of other philosophies. As a precautionary measure, you also seek out fragments of the Living Gate that have not yet awakened to sentience, and you destroy them as well, hoping to reduce the number of shardminds that will exist in the future. Most Shard Slayers are evil, and many are devoted to Vecna.