So. We got some upgrades for Reinhard in the past few months. Let's see what changes this brings to the table.
Base Reinhard vs Full Saber might be a fun match up. Saber's Excalibur is more powerful than Reinhard using normal sword, but Reinhard can dodge it with MHS reactions + his Blessings are not affected even if he hasn't drawn Reid. Base Reinhard can stalemate her with the right set of Blessings and speed advantage. Even with 7-C base form he is on par with Archer EMIYA/Fake Assassin/True Assassin in melee.
Reid Reinhard vs any version of Saber is... objectively a stomp.
The Gae Bolg's curse, which was able to hurt Saber, is way weaker compared to what some of the minor RZ Witches are capable of performing.
http://pastebin.com/XhMY5wg1
Finally, Pandora gives up controlling Greed and says ['Regulus can't be here. He is resting in his mansion with his harem.']
Greed suddenly disappears, and everything Greed touched is back to normal, even Petelgeuse's arms are back on.
Regulus is displaced hundreds of kilometers and several days back in time, with every visible damage he had caused until then rolled back, by Pandora saying two sentences.
We also have WoG that Reinhard cannot be harmed by any
RZverse curse or debuffs.
"
Magic Resistance: No curses, debuffs, or buffs can affect him."
So I'm sure Reinhard's magical defenses as shown in RZverse are stronger than Saber's.
On the other hand, Saber will not be able to prevent Reinhard's own curse from injuring her permanently, if Reinhard decides to invoke the Blessing of Death God. Saber was not able to heal through Diarmuid's Gae Buidhe, and as you've already seen an example of above, GB's curse isn't really any more complex compared to RZverse curses.
http://rezero.wikia.com/wiki/Divine_Protectio
The Divine Protection of Shinigami (µ¡╗þÑ×Òü«ÕèáÞ¡À Shinigami no Kago, "Divine Protection of Death God") was formerly used by Thearesia van Astrea. Slashes imbued with the Divine Protection's power leave wounds that are unable to be healed. The power of the Divine Protection increases the closer they are to the target, and the user can even reopen wounds others have if they are close enough and were originally inflicted by them.
http://rezero.wikia.com/wiki/Reinhard_van_Astrea
Divine Protectio (ÕèáÞ¡À Kago): Reinhard has the ability to wish for any Divine Protection he wants, such as the Divine Protection of Judgement (Õ»®ÕêñÒü«ÕèáÞ¡À Shinpan no Kago) during the battle at Priestella, and this ability is confirmed to be unrelated to him being the Sword Saint.
Given these curse/hax mechanics, Reinhard will defeat Saber by a pure battle of attrition, if nothing else - especially given the two Regenerationn feats below:
Reinhard has the Blessing of the Phoenix that will instantly regenerate him through death.
Unfortunately for them, Regulus grabbed Emilia's throat, forcing Reinhard to comply with his request, which was for him to take an attack without protecting himself in exchange for the hostages' freedom. Regulus took advantage of this by killing Reinhard in one strike, subsequently attempting to kill Subaru as well, however to their surprise Reinhard got right back up thanks to his Divine Protection of the Phoenix.
Reinhard can also regenerate, not just his own body, but a
entire shattered land mass far larger than Japa completely through a single sword swing. He will easily overpower any damage that Saber can deal through Excalibur.
Arc 4 Chapter 71 - Ending List
The voice at the very end was a voice that was filled up fully with clear contempt up until now. Upon hearing these words, Reinhardt took his sheathed sword out and raised it towards the sky. With the spirit of the sword embedded into it, a flash―the radiance of the sword's edge broke out along with a tremendous flare of heat―which cut into the sky, pierced into the atmosphere, smashed the surface, and churned his mana. Everything that got hit by the straight strike of his sword was bisected―light converged, and the world that Subaru felt in front of him turned into a state of disorder.
ÒÇî――――ÒÇì
The rejuvenation of the world covered in white, cold weather commenced after the slashing torrent. The gaps of the world were repaired, the round world created by the churned mana was restored, flowers budded on top of the earth's broken ground, the pierced atmosphere became filled with warm weather, and sunlight came into it from the broken sky. The world's demise and the world's rebirth occurred at the same time as a result of the sword's slash. And now, the slash caused the remains of the gigantic, lacerated beast to disappear thoroughly. Its remains disappeared to such an extent that not a trace of it would be left behind. The gigantic body that certainly should have had been there just a moment ago was nowhere to be seen, and even the waves of destruction caused by the gigantic body were nowhere to be found.
https://vsbattles.fandom.com/wiki/User_blog:Heinkel_Astrea/Re:Zero_-_Puck_%27World_End%27_minimum_AoE_calculatio
That absurd level of damage-reversal AoE magic right there, sir, is a healing capability that's waay out of context even for Avalon.
Anyway,
Reinhard is now an at least
High 6-C combatant who can stalemate an at least
High 6-A Witch without endangering himself. He is also at least MHS reaction speeds, so I doubt he can get blitzed. With these upgrades Reinhard will defeat 7-A Saber.