Depends on so many factors that it’s hard to tell. I see several scenarios here:
1) His Irregular power from back when he died. If this is indeed the case and he back then was as strong as Zahard I think right now he would be weaker than Zahard but stronger than some of the FHs. Maybe not all of them. People often say how FHs are much stronger now after thousands of years,but I don’t necessarily think it’s true. There was nobody to push them to get stronger and they were mostly chilling doing nothing,like Traum,so they are probably just a bit stronger than when they fought a war between themselves.
2) He only has powers of Bam and his knowledge and willingness to use them all as well as ability for doing so. In this case I would say he is quite a bit weaker than FHs,but much stronger than Bam was in any of his fights. We rarely see Bam utilize everything at his disposal,either due to him being tired or not wanting to or whatever reason. This case can be true because last few panels V said “Why do you hesitate”. To some extent it seems like he was literally saying “Why are you hesitant here,you have the power to change things,here let me show you”. It probably isn’t that,but something in his tone and manner of speaking is making me believe this is also a possibility.
3) His irregular powers from when he died + all of Bam powers… I mean this is just straight up broken, just thorn would be enough to boost any irregular powers into oblivion,I would assume in this state he would be easily as strong as Urek/Zahard if not stronger. This case is highly unlikely,but it’s not impossible,because SIU might have intended for V to stall Urek while Traum and Gustang battle it out.
4) Least likely option and I highly doubt it can be the case,but if he has all the powers of Bam + his own powers boosted by Arlene and outside god and what-not shenanigans… in this highly unlikely state he it would just be game over for whoever I would say.