Duelist
From Eldfall Chronicles
The target of this model’s Attack cannot use Combat Arts of level III or lower.
Community Answers (Discord)
Q: Does Duelist stop everyone from using Combat Arts I–III, or only the targeted model?
A: A model targeted by Duelist cannot use its I–III Combat Arts; if it declared such a Combat Art in reaction and is then targeted by Duelist, that Combat Art's effect is voided. Level IV is unaffected. (— Dockel)
Source: Eldfall Chronicles Rulebook v1.6, p. 71.
