IronStylus didn't give away too much info, but he left enough for fans of the game to ponder what the next champion will be like. So far, the only information that can be inferred from his post is that the next champion will be a female from Demacia, but with a streak of rebellion.
"They are the legions of blue and gold. They are the beacons of justice. They bear the standard. They lead the charge.
Demacia has always stood a stalwart sentinel against darkness and evil, but the nation faces a world of new and terrible threats. They wield the sword and spear, marching against their foes in mighty numbers, but can an army catch an assassin? Can numbers alone hold back spells woven in shadow and flame? With such vicious forces bearing down upon her doorstep, how will Demacia endure?
The answer is simple: a new champion approaches.
She is a new kind of hero, one of new mind and new method. One who can go where armies cannot reach, where swords cannot clash.
This is her story. Her worth will be tested, her ways will be questioned, but she will forge ahead. Honor guides her path. Justice steadies her aim. Valor is the only ally she needs."
Along with IronStylus' wall of text were two different images. They seem to be pages of a notebook or journal that this new champion possesses. However, this cannot be confirmed at the current juncture. More information on this champion should be revealed in the coming days, but for now we'll have to sit tight and wait for more news.