The ALMA Survey of 70 $\mu \rm m$ Dark High-mass Clumps in Early Stages
  (ASHES). II: Molecular Outflows in the Extreme Early Stages of Protocluster
  Formation
  We present a study of outflows at extremely early stages of high-mass star
formation obtained from the ALMA Survey of 70 $\mu \rm m$ dark High-mass clumps
in Early Stages (ASHES). Twelve massive 3.6$-$70 $\mu \rm m$ dark prestellar
clump candidates were observed with the Atacama Large Millimeter/submillimeter
Array (ALMA) in Band 6. Forty-three outflows are identified toward 41 out of
301 dense cores using the CO and SiO emission lines, yielding a detection rate
of 14%. We discover 6 episodic molecular outflows associated with low- to
high-mass cores, indicating that episodic outflows (and therefore episodic
accretion) begin at extremely early stages of protostellar evolution for a
range of core masses. The time span between consecutive ejection events is much
smaller than those found in more evolved stages, which indicates that the
ejection episodicity timescale is likely not constant over time. The estimated
outflow dynamical timescale appears to increase with core masses, which likely
indicates that more massive cores have longer accretion timescales than less
massive cores. The lower accretion rates in these 70 $\mu \rm m$ dark objects
compared to the more evolved protostars indicate that the accretion rates
increase with time. The total outflow energy rate is smaller than the turbulent
energy dissipation rate, which suggests that outflow induced turbulence cannot
sustain the internal clump turbulence at the current epoch. We often detect
thermal SiO emission within these 70 $\mu \rm m$ dark clumps that is unrelated
to CO outflows. This SiO emission could be produced by collisions, intersection
flows, undetected protostars, or other motions.
