Make damage screen ui image

Hello again.

You need to create a canvas, set its render mode option to "Camera Space" so it will be in front of the camera.

Make the canvas with all images (blood) you want at 0 transparency.

Then, you only need to add a CAnvasGroup compoennt, wich allows you to change the alpha value (transparency) of all images in the canvas toghater.

Watch the manual: https://docs.unity3d.com/Manual/class-CanvasGroup.html

So, by code, you only need to change this alpha value to 0 (100% transparent) at the start of the scene, and change the value whenh you recieve damage.

Bye!