His name is Canelo Alvarez. He will destroy cotto, expose GGG, and go down as the great fighter of the NEXT era. In the end it will be that Floyd Mayweather will have the only legit prime victory over him, and they will both go down as greater than Manny. PEACE
I do think Canelo can beat them both and we know he won't fear fighting Triple G if he handles business with Cotto.
I think as well Alvarez ends up beating Cotto and GGG by TKO11/SD respectively in competitive fight's. Alvarez is underrated as a fighter, both Cotto and GGG have styles that may favor Alvarez, who is a very competent boxer.
There is absolutely no way he beats GGG, sorry. Golovkin is a better puncher and has more skills. Golovkin will knock him out 9th round, perhaps earlier since he'll be wanting to make a statement.
GGG is the bigger puncher, but I disagree in the skills department. Judging both fairly I'd say GGG has the edge in. Footwork and punch placement, Alvarez in handspeed, defensively, & counter punching. If/When he beats Cotto he'd have been in way bigger fight's, so a huge experience edge as well. GGG is like a patient stalker, Canelo an aggressive counter-puncher. Stylewise I think it leads to a competitive bout.
Reality is, Canelo, if he fights Golovkin, will be smashed to bits (if fight happens in next two years ) and will be a win some lose some fighter against top middleweights.