If he will fight Manny Pacquiao he will just end up losing, but still, I am expecting a great fight between them.
If we pay for the ticket or the PPV, then it's just right to expect a great fight. Not being bias, but Mcgregor will only look like a kid facing a legend.
This is going to happen, it's not being bias, it's telling the truth, I hope that Manny would knock him out so he will stop challenging boxing superstars. 
Manny will just knock him out, though it won't be easy as we imagine right now but that would be the end result.
Mcgregor might be the superstar in UFC, but this will be his biggest mistake trying to face the all-time champion in boxing.