Regardless of the Arifureta Cosmology being infinite or what not, the range is specifically Interdimensional, meaning that it's limited and does not garant him the ability to travel to infinite Universes. The range would need to specifically be "Multiversal+" for it to save him from a 2-A BFR. Just check the
Range page to see that "Multiversal+" is indeed listed as a superior range than Interdimensional. A revision can be made to upgrade the value in Kouki page if the evidence is solid enough, but until then we should just stick with what is in the page.
Actually things like Multiversal+ and so are for when a character is able to affect everything in a infinite number of universe at the same time, interdimensional is specifically for when a character can travel between x number of universes through special means (like portals) but without having the ability to affect all of those x universes simultaneous, that is the entire reason of why the tp of arifureta characters are listed as interdimensional instead of something else.
And speaking of Absorption, I don't see that resistence listed in Kouki page, so from where does it comes from? Is it Magic in nature? Because if that's the case than he can also use AP attacks mized in with Power Null to nullify his resistence and than procede with the Absorption like he did with the other Strange.
The vitality absorption I mentioned before is listed as life manip resistance in the profile (it come from dark beings and ghosts), the soul absorption is listed as soul resistance (since Soul Shell grant resistance against spirit magic and spirit magic can do that), and the general resistance to haxs (including absorption) through the magic defence stat that I mentioned is still not applied to his profile since he is one of the profiles that I haven't update yet with the things from the
recent crt (I have be somewhat busy with other things). Kouki resistance to powerful have more than 24 layers and is both law& conceptual (type 2) in nature, so I honestly doubt Strange could null him unless his power null is smurf.
On top of this, Strange most popular and most used BFR is the Mirror Dimension, which is not performed throught portals but by simply
moving his hands (1:13),
rising his hands (1:16) or simply
launching the Dimension at the target (0:26). If Kouki is able to resist his Absorption, nothing stops him from just doing that.
Well, is debatable that the Mirror Dimension don't use portals because to send people to it they need to
pass through the crack in dimension Strange make, even against Mordo it seem like he waited until Mordo
touched the floor with the hand waiting until he touched the crack, so while not like the ring portals the Mirror Dimension still use portals, so Kouki can still dodge them (even more if you consider that there are also spells in Arifureta that create spatial cracks through spatial magic, and while those cracks are to destroy things instead of teleport the point of Kouki being extra careful against them still stand, specially since he would believe they are lethal like the spells he know). Also, Strange only use the Mirror Dimension to bfr when the opponent is in front of him at close distance (like a dozen meters or less), so he would need to get close to Kouki and if he do that then he is done with Kouki swordmanship (Strange will literally be unable to process his movements).
Additionally, just for curiosity, the Mirror Dimension is accepted as 2-A? Like that one need 2-A range to go and exit it, in principle that seem weird considering the closeness of the Mirror Dimension with the real world.
Side note but good old times when Marvel didn't abused the vfx companies and they had god tier special effects.
