So, I just played a Bot game out of fun, there was Shyvana Bot on Midlane fighting Ashe.
Shyvana played exactly till 15:30min and afterward walked to base and did nothing until the end of the game (31:48min)
15:30 Screenshot Shyvana on Level 10 was 1/0/0 with 63 CS and went back right after using her ultimate. http://prntscr.com/igmz2c
31:41 Screenshot right before we end the game Shyvana still Level 10 with 1/0/0 and 63 CS http://prntscr.com/ign0qc
I don't know what happened there that caused this. If you need the replay to check it for yourself tell me how to get it :D (since I don't know how haha)