- "No one must ever be allowed to reach Theodore in a battle... he tips everything into our favor."
Theodore's gift allows him to power up and strengthen the abilities of himself and others so they can access their ability to its greatest capacity, and so that they can reach a high level mastery and control instantaneously.
He cannot steal or give abilities, only enhance the ability of his targets.
A mental shield would not be able to block out his gift.
Theodore's gift is not long-lasting and the effects will fade over time. He can only maintain the enhancement of other people's abilities for so long before he has to stop. Also, it becomes more difficult for him to concentrate and maintain the enhancement if he is attacked.
As a human, Theodore's gift had been so strong it had manifested when he was human, bringing forth and strengthening his gift of persuasion.
Due to his gift, Theodore had no need to learn how to master it, or his other gift. He already knew how to. However, he did have to learn how to maintain his concentration.