Yu Yu levels are divided by rank, with Rank-S being the most powerful characters in the verse, the difference between an S-Rank even the weakest in this category for an A-Rank is colossal, an S-rank stomp easily an A-Rank . The problem is that there are only quantitative feats for high Rank-B. The rest is practically hype and powerscalle. So I don't even like to discuss Rank-A level, let alone Rank-S, all very speculative.
Yu Yu threads I only like to debate if it is Rank-B level or below
More if you consider all hype and declarations and powerscalle Rank-S at its strongest could be up to planet level. (Hiei is not a high-top tier Rank-S)