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The direct collapse scenario, which predicts the formation of supermassive stars (SMSs) as precursors to supermassive black holes (SMBHs), has traditionally been considered viable only in metal-free environments. However, the strong far-ultraviolet (FUV) radiation required to suppress fragmentation is more likely to occur in chemically enriched regions. In this talk, I will present results from radiation hydrodynamic simulations of star cluster formation in clouds with metallicities from Z = 10^-6 to 10^-2 Zsun, incorporating detailed thermal and chemical processes and stellar radiative feedback. Our simulations, extended to two million years, show that SMSs exceeding 10^4 solar masses can still form at Z less than about 10^-3 Zsun. Despite small-scale fragmentation, accretion flows are funneled into a few central stars through "super-competitive accretion." At higher metallicities (Z ~ 10^-2 Zsun), enhanced metal-line cooling induces large-scale fragmentation, suppressing SMS growth and instead forming dense clusters dominated by very massive (~10^3 Msun) stars. These clusters resemble young massive or globular clusters seen in both the early and local universe. Our results suggest that SMS formation remains viable below ~10^-3 Zsun, potentially increasing the number of massive seed black holes. Above this threshold, the same conditions naturally transition to dense stellar cluster formation, offering a unified framework for early SMBH and star cluster origins.