I highlight recent key advancements in the astrophysics of multiphase gas condensation in massive galaxies and its role in SMBH accretion. The high-resolution simulations show the soft X-ray plasma cools rapidly via radiative emission at the high-density interface of the turbulent eddies, stimulating a top-down condensation cascade of warm 10^4 K filaments. The ionized (optical/UV) filaments extend up to several kpc and form a skin enveloping the neutral filaments (optical/IR/21-cm). The peaks of the warm filaments further condense into cold molecular clouds (<50 K; radio). In the nuclear region, the condensed clouds collide in inelastic way, mixing angular momentum and leading to Chaotic Cold Accretion. CCA can be modeled as quasi-spherical viscous accretion with large fractal variance, which may explain the rapid AGN variability and is crucial to self-regulate the long-term AGN feedback cycle. The 3-phase CCA consistently reproduces the observations of cospatial multiphase gas in massive galaxies, as Chandra X-ray images, SOAR Hα warm filaments, Herschel [CII] emission, and ALMA giant molecular associations.
