If you look closely, you might spot a random symbol from Halo in Zack Snyder’s Justice League. It appears on Deathstroke’s sword and seems to have been added accidentally.

The apparent tie-in was even retweeted by Deathstroke actor Joe Manganiello. But not only does the symbol have nothing to do with Ra's al Ghul or the League of Assassins, it's just a modified ...