Please refer to this video for visual help: Illusionist - Level 50 Quest.
To start Illusionist's Level 50 Quest, speak with Sleyin in Silveria. (You must have completed Illusionist's Level 15, Level 30, and Level 45 Quests.)
She will give you Sleyin's Fifth Letter 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 and return to Sleyin in Silveria.
She will give you Sleyin's Sixth Letter, Thought Piece of Time, and Sleyin's Amulet. She asks you to investigate the Other World and look for Savius.
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 here is kill Otyus and Wyverns for their Tears.
Collects five Tears from each and head to the north. Speak with the Flame of Blue Soul and offer him the Tears.
The Flame of Blue Soul will give you Sparks of Blue Flame and Fire Ash of Soul. Double-click on the Sparks of Blue Flame and it will spawn Savius. Kill it to obtain the Thought Piece of Savius.
Once you have defeated Savius, use Sleyin's Amulet to return to Silveria and head over to Sleyin. Sleyin will give you Recommendation of Sleyin and Special Ore. Take the Recommendation and the Ore to the Blacksmith Bahturu. You will be awarded with the Sapphire Kiringku.
Illusionist Level 50 Quest completed!
- Sapphire Kiringku (26/26, safe to 6, +20 MP, Made of Gemstone, Weight 10, Illusionist only.)