The two witnesses will have, as Elijah had, "sealing power" (to seal the heavens, and prevent rain from falling).
Elijah appeared, with Moses, on the Mount of Transfiguration when Jesus was "transfigured" in appearance to Peter, James and John.
I believe the "keys of Elijah" (as prophesied in Malachi) were given them then; as also, I believe, were given them the "keys of Moses".
Jesus had promised just prior to this event that he would give his apostles the keys to "seal" or "bind" on earth, and what they "sealed" or "bound' on earth, would be "sealed" or "bound" also in heaven.
As a 'Latter-day Saint' (i.e., "Mormon), or member of "The Church of Jesus Christ of Latter-day Saints", I/we believe that these same "sealing" keys were also restored in our day. (We believe that after the death of the ancient apostles, since only they held these keys, these keys did not remain with "bishops" and others of lower or lesser priesthood office than "apostle"). This event, we believe, occurred on April 3, 1836, in Kirtland, Ohio, in the first temple constructed by the Latter-day Saints, according to a command from God to build it.
The following is the account of the appearance of Elijah. He appeared last. Jesus appeared. Moses appeared. And a person who lived in the days of Abraham referred in the revelation as 'Elias' also appeared. Moses, Elias, and Elijah all restored "priesthood keys", Latter-day Saints believe, to the prophet (and apostle) Joseph Smith, and also to one Oliver Cowdery.
1 THE veil was taken from our minds, and the eyes of our understanding were opened.
2 We saw the Lord standing upon the breastwork of the pulpit, before us; and under his feet was a paved work of pure gold, in color like amber.
3 His eyes were as a flame of fire; the hair of his head was white like the pure snow; his countenance shone above the brightness of the sun; and his voice was as the sound of the rushing of great waters, even the voice of Jehovah, saying:
4 I am the first and the last; I am he who liveth, I am he who was slain; I am your advocate with the Father.
5 Behold, your sins are forgiven you; you are clean before me; therefore, lift up your heads and rejoice.
6 Let the hearts of your brethren rejoice, and let the hearts of all my people rejoice, who have, with their might, built this house to my name.
7 For behold, I have accepted this house, and my name shall be here; and I will manifest myself to my people in mercy in this house.
8 Yea, I will appear unto my servants, and speak unto them with mine own voice, if my people will keep my commandments, and do not pollute this holy house.
9 Yea the hearts of thousands and tens of thousands shall greatly rejoice in consequence of the blessings which shall be poured out, and the endowment with which my servants have been endowed in this house.
10 And the fame of this house shall spread to foreign lands; and this is the beginning of the blessing which shall be poured out upon the heads of my people. Even so. Amen.
11 After this vision closed, the heavens were again opened unto us; and Moses appeared before us, and committed unto us the keys of the gathering of Israel from the four parts of the earth, and the leading of the ten tribes from the land of the north.
12 After this, Elias appeared, and committed the dispensation of the gospel of Abraham, saying that in us and our seed all generations after us should be blessed.
13 After this vision had closed, another great and glorious vision burst upon us; for Elijah the prophet, who was taken to heaven without tasting death, stood before us, and said:
14 Behold, the time has fully come, which was spoken of by the mouth of Malachi—testifying that he [Elijah] should be sent, before the great and dreadful day of the Lord come—
15 To turn the hearts of the fathers to the children, and the children to the fathers, lest the whole earth be smitten with a curse—
16 Therefore, the keys of this dispensation are committed into your hands; and by this ye may know that the great and dreadful day of the Lord is near, even at the doors.
(Doctrine and Covenants | Section 110:1 - 16)
I believe that the TWO WITNESSES spoken of in Revelations will be 'apostles'. They will have been ordained by those who hold these keys on the earth now, and will exercise those keys for the protection of the Jews. Also, after they have "tormented" people on the earth (in an attempt to get them to repent), by withholding the rain of heaven from falling upon them, everyone will rejoice, sending presents to one another, when they are killed, and allowed to remain in view for 3-1/2 days.
I can imagine how much clothing will be soiled when, with probably everyone in the world watching on television, they are resurrected, and ascend into heaven! THEN, the world will finally realize that these were holy men of God. And that Christ's coming is imminent! And those who have fought against and rejoiced over the supposed demise of these TWO WITNESSES are in 'deeper doo-doo' than what their clothing alone holds!