Causal Efficacy Without Svabhāva: How Can Dependently Arisen Dharmas Function?

Buddhist accounts frequently assert that phenomena (dharmas) are empty of intrinsic nature (niḥsvabhāva, asvabhāva), and that their arising, functioning, and cessation occur solely through dependent origination (pratītyasamutpāda). However, causal efficacy seems to require at least minimal stability of a phenomenon’s defining features. This raises some questions. 1. If dharmas have no intrinsic nature (niḥsvabhāva), how can they still perform functions ? Doesn't causal power require at least some stable feature, and if not, what does “causal efficacy” actually mean for empty dharmas? 2. Dharmas are described as momentary and empty. How do empty, momentary events form a causal continuum (saṃtāna) without presupposing some underlying stability?