Elixir of Skill gives Kayle early passive.

For instance if you use an Elixer of Skill you get your Passives of Divine Ascent at levels 5, 10, and 15, even before you level your ultimate, but just add soon as you level any ability.

Not sure if multiple Elixer of Skill could lower this further, however since Elixer doesn't raise champion level this doesn't seem intended.