According to the explanation that Desmond obtained from Titania that was later supplemented by Kyuru, the formation of an elemental seed was a fundamental step for the progress of any mana user.
Although both fairies did not explain the subsequent steps, Desmond knew that he was currently in a stage of mana accumulation, condensation, and purification, with the final result being the condensation of one elemental seed for each element he would master.
In theory, Desmond should have condensed his elemental seed during his advance to the three-star class, but that had changed thanks to Titania's gift. However, Titania's gift was more than just facilitating that breakthrough; her true gift was the unparalleled quality and purity of the elemental seeds she gifted Desmond with. Thanks to Titania's gift, Desmond's talent and potential in those three elements were only one level below that of a true Natura.