Trojans are invulnerable, except for a large crystal on their backs, and will rapidly turn to face their target. When fighting them with a group, whichever player the Trojan is currently tracking (usually the knight who has dealt it the most damage) should keep it facing away from the other players so they can attack. If fighting one solo, it is necessary to bait it into attacking and strike it from behind before it recovers, or use bombs, circling so the Trojan will turn its back to them. A good way to fight trojans while fighting them solo, is to stand far enough away from them to entice them to charge. Sidestep the upcoming charge and stand near enough to the Trojan to make it swing it's sword onto the ground. This should buy you plenty of time to get some hits in.
Trojans attack with speedy charges and stunning overhead sword swings, and also use a focusing move that raises their attack power while shocking and knocking back and damage knights who are too close. Its attacks require some charge-up and can be interrupted (though much force is required), and two well-coordinated players on opposite sides can potentially kill it without letting it attack at all. Trojans can also be tricked into damaging and stunning other monsters. In some cases, the Trojan can lock a stunned knight in place, preventing the player from moving.
Stun and Freeze-inflicting weapons and vials can prove helpful when fighting a Trojan, as it will be unable to move and will be open to attacks in its weak point.
There is a danger of being trapped in a corner by a Trojan, particularly when fighting solo, since most attacks cannot knock them back. A shield bump can push them slightly and allow you to escape, but it's easy to get your shield broken fighting one; some exceptionally heavy attacks, such as a Troika's charge or another Trojan's sword slam, can also push them.
When a Trojan takes enough damage, purple explosions emit from it, turning it into stone. Attacking a Trojan once it has become stone will cause it to shatter, dropping rewards.
Quick Glance Gear:
Mission: The Return of Ur, Trojans are known as the 'Legion of Ur,' and are said to have once numbered in the thousands, Devilites are trying to summon them into the Clockworks for unknown causes.
Monstrous Codex: Trojan
