I think Sonic does redeem Merlina in Black Knight? I think? Anyway, in Sonic Runners, Merlina pops up for the Easter Egg tournament that Sonic and the gang are participating in. Omochao asks Sonic to show her around and then no more story cut scenes are shown. I think there was something wrong with that story, as all the other stories were much longer. I'm betting the full story wasn't released. This is all from memory, so I could be a bit off, but I think I'm right.