I made a kineticist and chose Air element and Electric blast, but the character sheet lists me as now having Thunderstorm and Charged Water blasts, which have Electric as a prerequisite, but I don't have Air or Water blasts, which are also prerequisites for those. Also took only the Air blast and got Thunderstorm, Sandstorm, and Blizzard. I then tested with the Fire element and blast, and was granted the Blue Flame, Plasma, Magma and Steam blasts.
The Composite Blasts for those don't list more than one element.
Element air; Type composite blast (Sp); Level —; Burn 2
Prerequisites primary element (air), expanded element (air)
Blast Type physical; Damage half bludgeoning, half electricity
You batter a single foe with a gust of air crackling with electricity.