Using percent_visible makes it disappear from right to left (e.g, the last characters will disappear first). I'd like to achieve the opposite
You could probably just modify the text itself on a timer and just remove the first character in a loop. So create a timer that runs fast (the length of one character disappearing), and then use substr to remove the first character.
label.text = label.text.substr(1)
I haven't tested that but it might be something to look into.