S.C. Code § 62-1-108
For the purpose of granting consent or approval with regard to the acts or accounts of a personal representative or trustee, including relief from liability or penalty for failure to post bond, or to perform other duties, and for purposes of consenting to modification or termination of a trust or to deviation from its terms, the sole holder or all co-holders of a presently exercisable general power of appointment, including one in the form of a power of amendment or revocation, are deemed to act for beneficiaries to the extent their interests (as objects, takers in default, or otherwise) are subject to the power. The term "presently exercisable general power of appointment" includes a testamentary general power of appointment having no conditions precedent to its exercise other than the death of the holder, the validity of the holder's last will and testament, and the inclusion of a provision in the will sufficient to exercise this power.
S.C. Code § 62-1-108