Strider is a Warthwings which could obtained for free after finishing Chapter 2.
The battle was known as the 'Last War'. A group of Wing Guardians stood as the last hope and marched to the Greylands to find aid. They fought through hordes of Demons but were down to 2 soldiers; two brothers. The elder brother was heavily wounded, and his sword fell from his hands as the demons roared and charged. He had fought in many wars and killed countless demons, but he was just one man. He pushed his brother's hands away and asked him to escape. When the younger brother came back from the other side of the mountain with help, he only found his brother's armor on the desolate battlefield. Some say demons took the Guardian with them and tortured him until death. Some say the elder brother burned himself to death, but no one really knows what happened. The last Guardian took the armor and crafted it into Strider, which now symbolizes hope for the future.