To start Dragon Knight's Level 50 Quest, speak with Prochel in Behimous. (You must have completed Dragon Knight's Level 15, Level 30, and Level 45 Quests.)
He will give you the Fourth Order of Prochel and asks you to investigate the Crack in Time.
You will need to wait for the Crack in Time to appear on the mainland.
The Crack in Time appears randomly in one of ten locations so once it appears, ask around to find out where the Crack in Time is located. When the Crack in Time appears, it will stay open for three hours naturally. If the bosses inside are killed, however, then the Crack in Time will stay open for 24 hours.
Once you have located the Crack in Time, head inside and kill the monsters for the Fragment of Time.
Collect 100 Fragments of Time and return to Prochel in Behimous.
He will give you the Fifth Order of Prochel, Thought Piece of Time, and Prochel's Amulet. He asks you to investigate the Other World and look for Lucius.
Use the Thought Piece of Time and you will be teleported to an area called Goras that looks very similar to Dark Elf Holy Land. The Goras area has three kinds of monsters (Otyu, Wyvern, and Cracked Time). Otyus are aggressive but Wyverns and Cracked Time are non-aggressive. What you need to do in Goras is to destroy the Cracked Time for Otherwordly Thought Powder.
Collect 10 Otherworldly Thought Powder and head to the north. Speak with the Red Soul's Flame and offer him the 10 Otherworldly Thought Powder.
The Red Soul's Flame will give you Sparks of Red Flame and Fire Ash of Soul. Double-click on the Sparks of Red Flame and it will spawn Lucius. Kill Lucius to obtain the Thought Piece of Lucius.
Once you have defeated Lucius, use Prochel's Amulet to return to Behimous and head over to Prochel. Prochel will give you the Shiny Silver Bullion (Ingot). Show the Shiny Silver Bullion to Talion and he will give you the Weapon Material List of Talion. Take the Shiny Silver Bullion and the Weapon List to Blacksmith Pual. You will be awarded with the Destructor's Chain Sword.
Dragon Knight Level 50 Quest completed!
- Destructor's Chain Sword (16/10, Two Handed Weapon, safe to 6, +2 Hit Bonus, +1 Damage Bonus, Made of Silver, Weight 100, Dragon Knight only).