Abstract: I present a class of distant dust-enshrouded galaxies with extremely high luminosity, including several "Extremely Luminous Infrared Galaxies" (ELIRGs) that reach 10^14 L_Sun. Selected by their extreme red colors in WISE bands, their SEDs incorporating WISE, Spitzer, and Herschel photometry indicate hot dust dominates the bolometric luminosity. These sources are likely powered by highly obscured active galactic nuclei (AGN), are unlikely to be lensed. The existence of ELIRGs at z > 3 constrains the supermassive black hole (SMBH) growth history, suggesting that these SMBH's are born with large mass, or have a very rapid mass assembly, presumably by chaotic accretion. Their low source density (~ 10^-5 of LIRGs' at similar redshift) implies that these objects are intrinsically rare, or are a short-lived phase in a more numerous population. These sources have absorption-corrected X-ray luminosity significantly fainter than the mid-IR/X-ray correlation for AGNs, likely to be intrinsically X-ray weak. The ALMA C+ observation on selected sample shows a large, homogeneous velocity dispersion across few kpc, suggesting that gas is being blown away isotropically, possibility reflecting the stage of becoming unsecured quasars.  I will also discuss some of the follow-up effort using the Keck IFU to study the dynamics of the ionized gas in hyper-luminous systems.