Spoiler Thread: Avengers Infinity War
I'm thinking either that, or they do something like they did in the comics with Onslaught where Banner is "turned off" completely through some physic means (In the comics it was Jean Grey who did it, I think. Been a while since I read it, and I have no desire to revisit it) and he becomes "pure" Hulk with no Banner to hold his rage in check, and thus absurdly powerful even by Hulk standards.
I feel like this is leading towards a version of the Professor Hulk. The two personalities are going to come to some kind of understanding, maybe merge a bit. Probably not this level of intelligence, but he's been moving in that direction since Ragnarok.
I'm thinking either that, or they do something like they did in the comics with Onslaught where Banner is "turned off" completely through some physic means (In the comics it was Jean Grey who did it, I think. Been a while since I read it, and I have no desire to revisit it) and he becomes "pure" Hulk with no Banner to hold his rage in check, and thus absurdly powerful even by Hulk standards.