BH mass as a function of redshift. The broad Hα line detections from our stacks are shown as red filled stars, and 3σ upper limits for the nondetections are as open stars. Two large JWST BLAGN surveys are shown with light blue circles (A. J. Taylor et al. 2025a) and purple pentagons (I. Juodžbalis et al. 2026). The highest and second-highest [O III] luminosity stacks from S. Geris et al. (2026) are shown with cyan squares. We show the growth of a heavy 10⁴⁻⁵ M_⊙ BH seed with f_Edd  =  0.1 (gray shading), representing the typical Eddington ratio at lower redshifts (T. T. Ananna et al. 2022). We show three growth paths of a Pop III stellar remnant (10² M_⊙) with f_Edd  =  1 (solid black line), f_Edd  =  0.5 (dashed black line), and f_Edd  =  0.1 (dotted black line). In our models, the stellar remnant formed at z = 30, with accretion beginning after a 100 Myr delay.