There is no doubt that the world is emergent, and that the One who brought it into existence is the necessary being who we call “God”. But we can further build upon these facts, to prove that God is attributed with both Power and Will.
Given that God is the effecter of the world, either the world’s existence is necessitated by God’s existence, or it is not.
If God’s existence necessitated the world’s, then the world would have been beginningless. For if an effect’s existence were necessitated by the existence of its effecter, then the effect would exist so long as the effecter does. And since the effecter in this case is beginningless, then the effect would be beginningless as well.
However, we have already proven that the world is emergent. Therefore, the world’s existence is not necessitated by God’s existence.
And since God’s existence does not necessitate the world’s, it must be the case that God possesses the ability to bring the world into existence, despite His being beginningless. This ability to create is all what we mean by “Power”. Thus, God is attributed with Power.
Despite God’s ability to create the world, it was not necessary for Him to do so. God must therefore possess the ability to select between creating the world, and leaving it non-existent. This ability to select is all what we mean by “Will”. Thus, God is attributed with Will.
Necessity of Power and Will
Given the existence of Power and Will, they are either necessary for God or possible for Him. They cannot be possible for God. Therefore, they are necessary for Him.
The existence of Power and Will cannot be a mere possibility, because that which exists possibly, depends on an extrinsic specifier to bring it into existence. And if Power and Will were emergent, then this would have been a change on the part of God. This is impossible, since God is necessarily changeless.
Thus, Power and Will are necessary for God.
Genericness of their Relations
The potential relations (Ta’aluqat Suluhia) of God’s Power and Will, generically pertain to all possible essences. In other words, God is necessarily able to select existence for any possible essence by virtue of His Will. And God is necessarily able to bring into existence any possible essence by virtue of His Power.
This is true, because the alternative entails the specification of the two attributes. And what is specified depends on a specifier to select its specifications for it from the possible alternatives. This is impossible for God’s Power and Will given their necessity.
Thus, the potential relations of God’s Power and Will, generically pertain to all possible essences.
 If God were unable to leave the world non-existent, then the world would necessarily exist so long as He does. And since it is impossible for Him to not-exist, it would be impossible for the world to not-exist. This is false however, since we have shown that the world is emergent, and that God brought it into existence by virtue of His being attributed with Power.
 If it were possible for a quality to emerge for God, then God would have first existed in a state of lacking said quality, before transitioning into a state of being attributed with this quality. This is a change.
 More on this here.
 If God were unable to bring into existence any possible essence, then His Power would have been specified. Such that He would have been only able to bring some possible essences into existence, but not others.
 The specification of Power would be proof for its contingency. For if God were unable to bring into existence some possible essences, then either: God is unable to bring into existence some possible essences, because it is rationally impossible for Him to do so. Or God is unable to bring into existence some possible essences, even though He could have been able to bring them into existence. Both are impossible, therefore it is impossible for God to have been unable to create some possible essences.
As for the first (God is unable to bring into existence some possible essences, because it is rationally impossible for Him to create those possible essences), this is impossible because this possible essence would then not be possible. Since the potential for the existence of any possible essence is beginningless. Entailing that there exist at least one beginningless being that is able to actualize this potential. And God is the only beginningless being. Therefore, God is that being who can actualize the potential for the existence of any possible essence. More on this here.
As for the second, this is impossible because it would entail the contingency of God’s Power. Since God would then depend on an extrinsic specifier to determine which possible essences He is able to create, from those He is unable to create even though He could have been able to. And God’s Power is necessary.
Thus, it is impossible for God to be unable to create some possible essences.
The same reasoning applies to God’s Will, and His ability to select existence for any possible essence by virtue of this Will.