If you find that some of the environments in Senua’s Saga: Hellblade II to be too dark and/or other areas being overly bright, then you can check out this guide at Seeking Tech to see how you can find the brightness issues.
1. For the first potential fix, you can try re-calibrating the HDR brightness output.
To do so on an Xbox console, open the Pause menu and then select Settings > Graphics > HDR Calibration.
Follow the on-screen instructions to calibrate your console’s HDR to match your TV’s or monitor’s capabilities.
2. In the same Graphics menu of Senua’s Saga: Hellblade II, you can set the HDR Brightness and HDR UI Brightness to Bright.
3. If the brightness in the game still does not look right, then you can use the HDR Gamma slider to make further adjustments.
You may have to do this often when moving from a darker environment to a brighter one, and vice versa.