Nero Priest is a B-rank control unit with a niche anti-carry toolkit focused on silence and healing suppression. Even with these useful effects, he remains mostly a collection-level character in modern play.
Dark Curse is his defining utility: it can silence a target regardless of Status HIT and resistance, which is unusual and can disrupt key enemy turns. The tradeoff is that it also increases the target’s final damage, making bad timing very punishing againt some enemies. Barren adds steady anti-heal pressure on low-HP enemies with a high trigger chance, which can help close fights, but it is still conditional and not enough to make him a reliable control core. His direct damage is minor and mostly incidental.
Overall, Nero Priest is a situational budget disruptor with occasional tactical value in early progression or themed lineups, but his long-term role is very limited.