He would still be able to hear confessions and do Consecration. No?
That is invaluable in these times especially.
No heretic, schismatic or apostate can ever give a valid confession, but they can consecrate the Eucharist validly, although illicitly.
Heretics cannot give a valid absolution in confession, since all heretics, or people who are outside the Catholic Church, lacks jurisdiction.
There are something which is called supplied jurisdiction, but that is ONLY granted to all Catholic priests in necessity, so that they can give valid absolution to the penitent, but then again, this would only be granted to a non-Heretical Catholic priest, and not a heretic, schismatic or apostate.
St. Thomas Aquinas explains this as following:
St. Thomas Aquinas, Summa Theologica, Supp., Q. 38, Art. 2, Obj. 1: "The effect of absolution is nothing else but the forgiveness of sins which results from grace, and consequently a heretic cannot absolve, as neither can he confer grace in the sacraments. Moreover in order to give absolution it is necessary to have jurisdiction, which one who is cut off from the Church has not."
St. Thomas was here speaking about both am automatic excommunication for heresy, schism or apostasy, and a declared excommunication for sins of various kinds. A heretical priest can never be granted jurisdiction unless he convert from his heresy and joins the Catholic Church again, since he is outside of it as long as he remains in heresy, but an excommunicated Catholic priest who has lost his jurisdiction because of sins, is still a Catholic priest, although in state of grave sin. So since a priest who has been excommunicated for sins is still a Catholic, he would be granted jurisdiction in necessity.
The Council of Trent explains as following:
The Council of Trent, The Fourteenth Session, CHAPTER VII. On the Reservation of Cases: "Wherefore, since the nature and order of a judgment require this, that sentence be passed only on those subject (to that judicature), it has ever been firmly held in the Church of God, and this Synod ratifies it as a thing most true, that the absolution, which a priest pronounces upon one over whom he has not either an ordinary or a deligated jurisdiction, ought to be of no weight whatever... Nevertheless, for fear lest any may perish on this account, it has always been very piously observed in the said Church of God, that there be no reservation at the point of death, and that therefore all [Catholic] priests may absolve all penitents whatsoever from every kind of sins and censures whatever[/u]: and as, save at that point of death, priests have no power in reserved cases, let this alone be their endeavour, to persuade penitents to repair to superior and lawful judges for the benefit of absolution."
So, as we've just seen, no heretical, schismatical or apostate priest, can ever give a valid absolution, that confession was thus invalid. This would make all confessions buy almost all priests in the entire world invalid, since almost all priests are heretics, who either accepts an antipope as pope, or believe in one or more heresies.
Fr. Demaris, a Missionary of St. Joseph and professor of theology in Lyon, France, and who remained faithful during the upheaval caused by the French Revolution, when many priests had apostatized by joining the French Constitutional Church, he speaks to Catholics how God will remit their sins if they make a sincere confession to God along with the promise to confess to a Catholic priest when one becomes available. He speaks of making a good confession, just as they would if a Catholic priest were available:
Fr. Demaris: "Removed from the resources of the sanctuary and deprived of all exercise of the Priesthood, there remains no mediator for us save Jesus Christ. It is to Him we must go for our needs. Before His supreme Majesty we must bluntly tear the veil off our consciences and in search of the good and bad we have done, thank Him for His graces, confess our sins and ask pardon and to show us the direction of His Holy Will, having in our hearts the sincere desire to confess to His minister whenever we are able to do so. There, my children, is what I call confessing to God! In such a confession well made, God himself will absolve us. It is thus in all painful situations that deprive us of the Sacraments. The carrying of the Cross like a Christian is the source of the remission of our sins…
"…Console yourselves, my children, in the trust you have in God. This tender Father will pour on you His graces, His blessings and His mercies in these awful moments that you fear, in more abundance than if you were being assisted by His ministers, of whom you have been deprived only because you wouldn’t abandon Him. The abandonment and forsakenness that we fear for ourselves resembles that of the Savior on the Cross when He said to His Father, 'My God, my God, why hast thou forsaken me?'…Your pains and abandonment lead you to your glorious destiny in ending your life like Jesus ended His! …Don’t be surprised at the great number who quit! Truth wins, no matter how small the number of those who love and remain attached to God. God watches over us, our hope is justified. It tells us that either the persecution stops or the persecution will be our crown. In the alternative of one or the other, I see the accomplishment of our destiny. Let God’s will be done, since in whatever manner He delivers us, His eternal mercies pour into us."
So, as explained above by Fr. Demaris, God will not abandon us if we remain faithful to Him. The last test in this great apostasy and the end of the world WILL BE ABOUT OBEDIENCE TO GOD AND HIS COMMANDMENTS, and not about receiving illicit, invalid, blasphemous sacraments from the hands of priests who confects these sacraments in a state of mortal sin! We have no reason to approach a heretical or schismatical priest, since we have no obligation to do so, and neither can such priests ever give us a valid confession or absolution, neither can they give us a licit Eucharist, but only a blasphemous and mortally sinful Eucharist unto our own damnation, if we persist in obstinately approaching a heretical or schismatical priest for mass and the sacraments. If we eat Jesus unworthily, we eat Him unto our own damnation (1 Corinthians 11:29).