TurningTide adds a small UI element when a user is wearing the Turning Tide set.
It displays BASH when a bash will apply Major Vulnerability to enemies in front of the wearer.
It will display DOWN when you can no longer apply Major Vulnerability (due to either losing the buff, or by applying Major Vuln earlier)
It also includes a cooldown timer that counts to the next time where upon blocking you'll be able to apply Major Vulnerability again.