Catholics believe neither that it is possible to kill Christ again, nor that the Mass is a "re-killing" of Christ:
268 A. ... in the Mass there is no real shedding of blood nor real death, because Christ can die no more. Baltimore Catechism
265 A. The Mass is the same sacrifice as that of the Cross. Baltimore Catechism
I grew up Catholic and went through 8 years of Catechism
It's unfortunate you didn't pay attention because if you had you wouldn't have so many misconceptions about the Catholic Church.
Then one can certainly remember, because it is a memorial "This do in remembrance of Me."
His Body was prepared by God, in order that it be a perfect Sacrifice [Heb 10:5]. In remembrance of His Death on the Cross of Calvary that purchased our Redemption, which we celebrate in that referred to as "the Last Supper". It was intended to be, and still is a memorial celebration, not a sacrifice again, and again, and again..
So, there is no more need for sacrifice as the following scripture will clearly define
Hebrews 10:1 For the Law (the Law of Moses) having a shadow of good things to come (the Law of Moses was only meant to be temporary; it portrayed Christ Who was to come),and not the very image of the things (it was quite impossible for the Law to present a proper image of Who and what Christ would be; it suggest such, but was only a suggestion), can never with those Sacrifices which they offered year by year continually make the comers thereunto perfect. (The animal Sacrifices could only cover sins, they couldn't take away sins. That remained for Christ to do [John 1:29]
Hebrews 10:2 For then would they not have ceased to be offered? (Paul asked this question simply because the fact that the animal Sacrifices had to be offered over and over proclaimed their insufficiency. They were, in reality, only a stopgap measure.) because that the worshipers once purged should have had no more conscience of sins. (This proclaims what the Proper Sacrifice of Christ could do, and did do. The phrase, "no more conscience of sin," should not be misunderstood as "no more consciousness of sin.")
Hebrews 10:3 But in those Sacrifices (animal Sacrifices)there is a remembrance again made of sins every year (That the High Priest of Israel had to go into the Holy of Holies once a year with animal blood proclaimed the fact that this system was basically flawed, and was meant only to point to Christ Who was to come.)
Hebrews 10:4 For it is not possible that the blood of bulls and of goats should take away sins. (The word "impossible" is a strong one. It means there is no way forward through the blood of animals. As well it applies to all other efforts made by man to address the problem of sin, other than the Cross.)
Hebrews 10:5 Wherefore when He (the Lord Jesus) comes into the world (presents Christ coming as Saviour, Who undertakes in Grace to meet every claim the Throne of God has against penitent sinners), He said, (Psalms 40:6) Sacrifice and Offering You would not (refers to the fact that He would pay for sin, but not with animal Sacrifices), but a Body have You prepared Me (God became man with the full intention that His Perfect Physical Body was to be offered up in Sacrifice on the Cross, which it was; the Cross was ever His destination):
Hebrews 10:6 In Burnt Offerings and Sacrifices for sin (proclaims the root of the problem which besets mankind--it is "sin"; the idea is, that the Sacrifices were not sufficient as it regards "sin"; therefore God took no pleasure in them in that capacity) You have had no pleasure.
Hebrews 10:7 Then said I, Lo, I come (in the Volume of the Book it is written of Me,) (The entirety of the Old Testament points exclusively to Christ, and in every capacity.) to do Your Will, O God. (The Cross was the Will of God because it had to be if man was to be Redeemed.)
Hebrews 10:8 Above when He said, Sacrifice and Offering and Burnt Offerings and Offering for sin You would not (refers to the fact that animal Sacrifices could not cleanse from sin), neither had pleasure therein (concerns the insufficiency of the Sacrifice); which are offered by the Law (refers to the fact that all these Offerings were included in the Mosaic Law; even though instigated by God, they were meant to point to Christ)
Hebrews 10:9 Then said He, Lo, I come to do Your Will, O God. (The doing of the Will of God, as it regards Christ, pertained totally and completely to His Sacrifice of Himself on the Cross.) He takes away the First (the Old Covenant which He did by the Sacrifice of Himself), that He may establish the Second (The New Covenant which He did by going to the Cross, the only way it could be established).
Hebrews 10:10 By the which will (the Sacrifice of Christ took away the First Covenant, satisfying its demands, and established the New Covenant) we are Sanctified through the Offering of the Body of Jesus Christ once for all (this proclaims unequivocally that the only way the Believer can live a victorious life is by the Cross ever being the object of his Faith.)
Hebrews 10:11 And every Priest stands daily Ministering and offering oftentimes the same Sacrifices, which can never take away sins. (proclaims the insufficiency of this method)
Hebrews 10:12 But this Man (this Priest, Christ Jesus), after He had offered one Sacrifice for sins forever (speaks of the Cross), sat down on the Right Hand of God (refers to the great contrast with the Priest under the Lenticular system, who never sat down because their work was never completed; the work of Christ was a "Finished Work," and needed no repetition);
Hebrews 10:13 From henceforth expecting till His enemies be made His footstool. (These enemies are Satan and all the fallen Angels and demon spirits, plus all who follow Satan)
Hebrews 10:14 For by one Offering He has perfected forever them who are Sanctified. (Everything one needs is found in the Cross [Galatians 6:14];)
Hebrews 10:15 Whereof the Holy Spirit also is a witness to us (a witness to the Cross): for after that He had said before (refers to the fact that the Holy Spirit has always witnessed to the veracity of the Finished Work of Christ),
Hebrews 10:16 This is the Covenant that I will make with them after those days (proclaims its distinctive feature as being the Sanctifying Work of the Holy Spirit Who would be caused to take up His permanent abode in the Believer, all made possible by the Cross), says the Lord, I will put My Laws into their hearts, and in their minds will I write them (the work of the New Covenant, which accompanies the Born-again experience);
Hebrews 10:17 And their sins and iniquities will I remember no more (He has taken them all away, and did so by the Cross)
Hebrews 10:18 Now where remission of these is (with all sins Atoned, the argument is settled), there is no more Offering for sin. (No more offering is necessary, for Christ paid it all)
Hebrews 10:19 Having therefore, Brethren, boldness to enter into the Holiest by the Blood of Jesus (the Cross has made it possible for any and every Believer to come into the presence of the very Throne of God, and at any time so desired)
Hebrews 10:20 By a new and living way (presents the New Covenant), which He has consecrated for us (by the Cross), through the Veil (contains an allusion to the Veil which separated the Holy of Holies from the Holy Place in the Tabernacle), that is to say, His flesh (refers to giving Himself on the Cross, which opened up the way to God);
Hebrews 10:21 And having an High Priest over the House of God (the actual Greek says, "a Priest, a Great One"; He is the Head [Col. 1:18];
Hebrews 10:22 Let us draw near with a true heart in full assurance of Faith (Faith in the Finished Work of Christ), having our hearts sprinkled from an evil conscience, and our bodies washed with pure water. (This portrays Paul using Old Testament Types to represent the reality we now have in Christ [Lev. chapters 8-9],)
Hebrews 10:23 Let us hold fast the profession of our Faith without wavering (Faith in Christ and the Cross); (for He is faithful Who Promised;) (This refers to the fact that everything the New Covenant promises, which is Salvation and total victory over all sin, will be realized in totality.)
Brother, based on the above scripture, it can only be concluded that the world has been dealt a Judaized form of Christianity in an attempt to retain the Old Levitical sacrificial system only this time in an unbloody manner.
For it is written: Hebrews 9:22 And almost all things are by the Law purged with blood; and without shedding of blood is no remission
Let us continue....
Hebrews 9:23 It was therefore necessary that the pattern of things in the Heavens should be purified with these (everything that retained to the Tabernacle and all of its Sacred Vessels was a copy of that which was in Heaven; inasmuch as the Vessels and Tabernacle were touched by men, they had to be purified by Blood, OE "animal blood"); but the Heavenly things themselves with better Sacrifices than these (If man were to enter Heaven, the abode of God, there would have to be a better Sacrifice than that of animal blood)
Hebrews 9:24 For Christ is not entered into Holy Places made with hands(Christ did not enter the earthly Tabernacle or Temple, regarding the offering up of His Precious Blood on the Mercy Seat) which are the figures of the true. (presents the fact that these "figures" were only temporary); but into Heaven itself, now to appear in the Presence of God for us (presents the purpose and reason for the Cross; all of it was done "for us")
Hebrews 9:25 Nor yet that He should offer Himself often (read that verse again; refers to the fact that the one Sacrifice of Christ which was the Offering of Himself on the Cross, was eternally sufficient for the cleansing from all sin....past, present, and future; it will never need to be repeated, as the High Priest enters into the Holy Place every year with blood of others (refers to the High Priest of Israel of Old, who went into the Holy of Holies once a year on the Great Day of Atonement, carrying animal blood)
Hebrews 9:26 For then He (the Lord Jesus) often have suffered since the foundation of the world (presents the fact that He wasn't functioning as the High Priest of Israel who, as stated, had to offer Sacrifice yearly) : but now once in the end of the world has He appeared to put away sin by the Sacrifice of Himself. (this presents the One Sacrifice of Christ as sufficient for all time. The end of the world= "in the consummation of the ages" As well, by the Sacrifice of Himself, he didn't merely cover sin, but rather took it away [Jn 1:29])
Hebrews 9:27 And as it is appointed unto men once to die (due to the Fall, all men are under a sentence of death, and in fact all have died Spiritually, which means to be separated from God. That's why YOU, as directed by Jesus Himself says "You Must Be Born AGAIN" this time of the SPIRIT!), but after this the Judgment (the answer to the Spiritual death of man is Christ and what He did at the Cross; if Christ the Saviour is rejected, all will face Christ the Judge; for as death was inevitable, the Judgment is inevitable as well.)
Hebrews 9:28 So Christ was once offered to bear the sins of many; and only them who look for Him shall He appear the second time without sin unto Salvation. (this refers to the Second Coming. "Without sin" refers to the fact that the Second Coming will not be to atone for sin, for that was already carried out at the Cross at His First Advent. The Second Coming will bring all the results of Salvation to this world, which refers to all that He did at the Cross. We now only have the "First-fruits" [Romans 8:23]
The problem with the world and the Church as well, is that it has ever sought to substitute something else in place of God's plan for Salvation. But let all know, it is alone the Cross! the Cross! the Cross!
Just as He went, we all must go.. The Way of the Cross
I sincerely hope and pray, just as the Lord does, because He is forever interceding for us, that you might find your way to His Way, the Way of the Cross. God Bless