It's not exactly a asset. The life bar is composed by 5 diferent actors placed in front of each other so they look like a single element. I used the "pin to screen" function on each of these actors. I used a variable to represent the life and set it to 5 on init. When hit by a enemy, two custom events are called, one to decrement "life" by 1 and other to hide the first life bar actor if "life = 4", the second if "life = 3" etc