Invoke the Singularity

Convoke, improvise
Put a number of +1/+1 counters on each creature
that convoked Invoke the Singularity equal to the
number of artifacts that improvised it.
Put a number of +1/+1 counters on each artifact
that improvised Invoke the Singularity equal to
the number of creatures that convoked it. If
these artifacts weren't creatures or Vehicles,
they become 0/0 construct artifact creatures.