God’s omnipotence is independant of outside things, because He is God.
Souls who do not want eternal life choose to go to Hell. So it is not God’s fault but a soul’s, for it is the soul which chooses poorly. God gives the soul every grace necessary for salvation at the hour of death, yet if the soul dose not want eternal life, than it has spurned God’s Mercy, and He will leave it in its misery (Hell). He dose not force anyone to love Him, nor He dose force anyone to accept eternal life, which is a great grace of His. (Graces are free and undeserving gifts of God’s Mercy which are given for man’s own good)
Satan has lost the battle against God at Calvary, when Jesus defeated sin and death, and this defeat will ultimately come to realization at the Second Coming of Jesus, when He will save His Church from her enemies and will judge the living and the dead. It is true that every damned soul is a victory for the devil in his struggle aganst God, but, ultimately, he has lost the war against Heaven. God asks us to help Him save souls by prayer and sacrifice; it is a mystey as to why He allows us to cooperate with Him.
God’s glory and honor is not diminished in Hell. It is true that, for every losr soul, that is one less soul who praises God in Heaven, but, the damned give glory to God’s Justice, for they are justly punished. Yet they do not give such glory willingly, but unwillingly, for if they could, they would cease to exist, just to spite God’s Justice, which they hate with all their being, since their wills are eternally set against goodness, in light of their choosing Hell. Moreover, God’s Mercy dose reach into Hell, not in the sense that He relieves the damned but in the sense that He dose not give them the punishments which they deserve. Indeed, if He punished them as they deserved, they would not be able to bear it. But He has pity even on them, and so, though they do suffer intensely, they do not suffer as much as they could. So, in that sense, they give glory to His Mercy. But again, it is unwillngly, for they hate His Mercy. They despise God with all their being and would like to see every creature join them in Hell, just to spite God, who is Justice, Mercy, Love - in a word, Goodness itself.