'Nothing is true, everything is permitted' wasn't an excuse for people to do anything they wanted. People learned the combat skills in Assassin's Creed not to become war machines who knew nothing but killing.
When Altair killed the last templar knight, he found that his mentor was also a templar knight. The latter intended to use him to kill the other nine templar knights and become the sole owner of the Pieces of Eden.
It took Elina a long time to reach the end of the plot.
In the ordinary difficulty level, Altair had recovered all his strength by now, making the battles less difficult than she had imagined.
After defeating his mentor, Altair said to the Piece of Eden, "What do you bring to us? Faith or destruction?"
When Sala saw this, an indescribable sadness spread in her heart.
"When other people's minds are blinded by the so-called truth, remember - nothing is true."