Choosing the skill was not tough. There were two Supreme rank skills and Arkhen chose one of them. The main problem with all skills was that none of them were Fire or Vanquish affinity-based.
In the end, he chose a Shield/Recovery-type skill since he had none like those.
[Aegis of Life Conversion]
[-Rank: Supreme]
[-Affinity: Life & Water]
[-Class: Maxed]
[-Cost: 1,000 Inomiz energy / 1,000,000 Primal energy]
[-Effect: Conjures three Aegis orbs around you that automatically extend a water barrier whenever an attack nears you. The damage suffered by the barrier is converted into a healing force, which you can use to heal yourself or anyone within five kilometers of yourself. You can also use an orb to heal anyone directly as they already contain powerful healing force]