At the time of Ao Shin's reveal, it was known that at least two champions (now known to be and ) were scheduled to be released before him.
Due to production difficulties, Ao Shin was delayed and at the time was not expected to be released until 2015.  His release was further delayed to early 2016 because of kit, tech and theme difficulties regarding the champion.  
A new Dragon Champion named is confirmed to be Ao Shin's spiritual successor.
- Champion Sneak Peek
By sixtwo 
As the League of Legends community expands and grows around the world, so too do our influences and inspirations for the game. We thought it would be fun to give you guys a very early peek at one of the champions we're working on while he's still in the early stages. Meet Ionia faces its greatest crisis, Ao Shin will descend from the sky., a powerful storm dragon and guardian of the natural world. Legend holds that when
Let's start with the inspiration for his name: Ao is the family name of the mythological dragon kings, who rule water and weather. This tells us right away that this is a powerful, elegant being, above the concerns and rules of men. Shin can mean many things, one of which is prosperity. It also means a rising storm. Ao Shin embodies this elemental duality, capable of raining good fortune on his allies and, in the very next breath, bringing stormy, thunderous ruin upon his foes.
The community's been asking for a dragon champion for some time, but we knew we couldn't just do any dragon. With each new champ, we try and push the limits of what's technically and creatively possible. Ao Shin is no different. One of the challenges we're looking forward to tackling is how to capture his unique anatomy and movement in a way that brings a new dimension to the champion pool. It's too early to go into much detail, but we're really excited about the ways this champion will move across the battlefield.
Ao Shin isn't the next champion scheduled to come out, so he's still a ways off and many things are still subject to change. But we wanted to share our inspiration with you and give you a look at the early thought processes that go into champ design. Hopefully you're as excited about his potential as we are to keep working on him!