I've been trying to unlock Tennou's head for the Shugoki since I had him at Rep 22 which was a few days after the E3 2018 announcement. He is now Rep 35 and I still haven't been able to unlock it. I've tried multiple loot crates and a weeks worth of championship status. Duel Tournament seems to yield no more loot than standard Duel. Is this a bug or was the loot system really designed this way?
I've also noticed that with other characters it doesn't take too long to unlock the first two pieces of a weapon set but the final piece seems to take significantly longer but my experience with the Shugoki is the worst. I made him go up 13 Reputations trying to unlock the final piece of a weapon set to no avail. The thing is, if I spent that time on another character from scratch then it would be looting legendary gear by now.
Update:
Finally, at Rep 36, I've unlocked the Tennou's head piece to complete the weapon for my Shugoki. This was during the Loot Fest and I also had Champion Status for the occasion. I'm glad but the 14 Reputation wait was far too long since, again, that is enough to build up a new character to a high level from scratch. So the loot system is still an issue.