What we have right now is; Profane>Siren>Pirate (Max), in both awakened and true stages.

But of course this is subject to change in the future so we can get Cheap Blade And Soul Gold legendary weapons.

It differs from version to version tho, but after looting around for information this is the guesses I’ve gathered up.
-The new path will be Profane>Oathbreaker>Breeze
-True Siren can directly go into True Oathbreaker, and True Pirate into True Breeze
-True Pirate weapons can be dismantled to obtain a +20 attack power soul, but this is something that apparently won’t be added in the EU version. (Only in other versions)
-Legendary weapons are obtained somewhere in that path(?)
-In April Patch, we’ll possibly get Oathbreaker, so reaching Awakened Pirate before that is a good effort
-If you have a True Pirate, reaching Legendary will be somewhat cheaper than going from Profane to Legendary
-All in all, the best thing you can have right now is True Pirate, and it’s the most efficient thing as well considering going to Legendary

That’s all the guesses, if anyone has any solid true information please share.
Just no more guesses since there’s too many around.

Profane>Oathbreaker – confirmed (and partly in the client)
True Siren > True Oathbreaker – confirmed
True Pirate > True Breeze – confirmed (and also already in the client)
Pirate Soul from dismanteled True Pirate – 99.9% confirmed we won’t get that
There will be at least 2 different legendary weapons. One from upgrading the Hongmoon weapon to max (with 2 options available) and one where we currently have no information how to obtain it but it will be seperate from the Hongmoon weapon path.
I also expect lvl 50 and Oathbreaker/Breeze in April but nothing confirmed right now.
The cost to upgrade may be cheaper in the new oathbreaker path in our version but it will need more Blade-Soul Gold material from the new areas so it will take longer to catch up in the first few weeks. Running lvl 50 dungeons with Oathbreaker is much harder than with Pirate.