For Aëyr, I choose to upgrade her [b]Slippery[/b], and give her [b]Acrobatics[/b]. As for customs, I upgrade [b]Going the Distance[/b] and add [b]Burning Fast on an Empty Tank[/b].

[b]Going the Distance[/b]: [i]A skilled runner, she is both fast and enduring, able to make long treks with great speed and little sustenance.[/i]
[indent]{Increases speed and endurance while running.} [b]Level 2[/b][/indent]
[b]Burning Fast on an Empty Tank[/b]: [i]Even after exhausting herself completely, she can push herself to the same speeds with but a moment's rest.[/i]
[indent]{Decreases recovery time.}[/indent]