Today, I found a Traitor Champion Blue Whale in the South West area of Release. After a short bit of combat, I had to back off to tend some wounds, and prepared to finish him off. While bandaging on my boat, I watched as he started moving to the West, crossing the server border, and simply vanishing from existence (had him selected and targeted, both immediately switched to nothing selected). There is a Rowing boat near the area named "Zora's Hand" at roughly T8 on the in game map. The mission is still active (it had just started 30 minutes prior), but the creature is simply gone.
Name: Everyone: Magranon's jest
Started: 5/27/18 11:29 AM
Expires: 6/3/18 11:29 AM
Difficulty: 7 / 7
Description: Magranon commands you to slay the traitor champion Blue whale seen fleeing from Valrei to these lands. It was last spotted in the southwest regions.
Rewards: 15m sleep bonus for the person who completes this mission as well as 3500 karma per creature with 210m extra sleep bonus split between participants upon completion (30m max each)