Nucky Thompson

With regard to the topic, I think that Aeron's adventures and the invasion of the Others will be closely related and he will organize their transport by water as a means to rid himself of Euron, or something along those lines... Unfortunately, he has quite the plot armor. And will probably die in a flashforward at the end of the series, where he is, as Tyrion himself described, aged 90, in his own bed, with a bellyfull of wine and a girl's mouth around... Nevertheless, we can reasonably hope that Victarion will do the axe treatment to the multitude of Meereneese character, along with those from Yunkai, Astapor and whoever else is around.

Seconded. He can rid us of a multitude of annoying Meeren characters in one fell swoop. Wonder if that would actually turn out to be GRRM's solution to the 'Meereneese knot'?

What is more, what he knows of the Greyjoys, doesn't add up to their fleet showing up at Meereen: Barristan assumes that the powerhungry Balon and the battlehungry Victarion would at once gnaw at Westeros mainland if given the opportunity, and have a complete lack of the foresight to extend their reach as far as Meereen. He forgets about Euron, who is actually the Greyjoy visionary, as he had been in exile at the time Barristan was back in Westeros. That's why he thinks of Theon, who might have been sent on behalf of the King in the North to seek out an alliance (and knowing about the "Usurper's dogs" attitude, probably thinks it unlikely). It is rather unlikely that the Iron Throne would go out in force to seek an alliance with a Targaryen, and sending the Greyjoys to destroy her seems insufficient from a military standpoint, all the while the Iron Throne has domestic problems to deal with and can't spend its armies in such ventures. And, of course, he still thinks that Theon is loyal to the Starks.

Now that's a happy ending to this particular storyline! GRRM can't believably make Daenerys leave Slaver's Bay, so he sends in an Ironborn reaver with a potential to control dragons to the rescue! With such an arsenal at his disposal, Victarion will be able to reave and pillage to the best of his ancestors' practices. Moreover, it will provide closure to a particularly irritating storyline. It is also notable that Victarion's name foreshadows him being victorious (at least once) before he dies. What better opportunity than some incompetent slaver armies on stilts besieging a city full of morons? He will be doing them all a favour, really...

Selmy is described as the greatest fighter alive and his greatness cannot be wasted by battling savage foreigners alongside "warriors" on stilts. He is destined to do something great and sacrifice himself for his monarch, but this should happen in Westeros. Barristan will outlive the Meereneese knot.