Ever wonder what the green icon is for on the hero avatar? The one at the upper-left corner in a match-up game? See screenshot above.
I noticed that the icon is on and off, but I don’t really have an idea what it is for.
After a few observations and tests, it appears that it indicates the availability of the ultimate or third skill of a hero. Feel free to correct folks!
The green disappears once a hero casts his ultimate.