Warrior talent · row 6 of Protection, from level 35 (30 with Talented 5/5) · Physical

Bastion

Increases all damage you deal by 2/4/6/8/10% while a shield is equipped.

Game files · build 1.60.1.70245Read from the WoW Forever beta client, build 1.60.1.70245.

Compared with Classic

Classic tooltip

Increases the damage you deal with One-Handed Melee weapons by 2%.

Data	Classic	Forever
effect 1 value	2	10

What Blizzard said about Bastion, each line checked against the files.

Matches the files
Swapped the positions of the Bastion (Row 5) and Focused Rage (Row 6) talents.
Developers' note: We wanted to give players Focused Rage sooner to smooth out progression, as opposed to more damage from Bastion. This should smooth out some of the feeling while leveling as Protection before obtaining Shield Slam.
The files The client files still put Bastion (16538) in row 5 and Focused Rage (29787) in row 6. Blizzard's hotfix data captured on build 70245 moves Focused Rage to row 5 and Bastion to row 6, which is the swap.
Bastion Focused Rage Development Notes, September 24
Changed since
Bastion: New row 5 talent. Increases all damage done while you have a shield equipped.
The files It's Classic's One-Handed Weapon Specialization (same spell 16538), now +2-10% damage with a shield. It was Protection row 5 in 70170, and the 70245 hotfix moves it to row 6, which Blizzard's Oct 2 post doesn't mention.
Bastion Class deep dives: Priest and Warrior

69876 Sep 16First beta build we archived. No changes in the client files since.