Name change in Yasuo after getting a pentakill?

So today, I was playing ranked in silver 4, mid lane as yasuo. I got fed off of their enemy fizz, started snowballing until my entire team died at rift hearld pit. I snuck up behind them and got a 5 man ult, 4 of them died and one managed to escape with flash. I pushed up mid lane and saw my pentakill waiting for me under the tower. I got the delayed pentakill, and their riven said through all chat that I was fed, to which I replied to, and instead of saying Zero Esper (Yasuo) next to my response, it said Zero Esper (Seal) for that one chat in the message. I do not have a screen shot of this, since I didn't know how to take a screen shot on my computer. However, if there is any way to read through the chat log of my most recent Yasuo game, I recommend looking at it.