TERA are in for a special treat, as the game is incorporating a crossover with the popular anime series Attack on Titan. The crossover, which was made in conjunction with Kodansha, adds time-limited costumes and special “BAMs” to fight.
The costumes will require some luck (and probably a lot of money) to get, as they are only available through the gacha system. The event is currently running with no word whether or not it will make its way over to the North American servers.
Source: TERA Europe