With GNU awk (version 4.x) try this:
awk 'ENDFILE { printf "%d %s %s %s\n", ++c, $8, $9, $10}' *mcp > "${Pout}${output}"
echo "Finished Looping through each file."
With other awks and shells like bash try:
for f in *mcp
do
awk -v c="$((++c))" 'END { printf "%d %s %s %s\n", c, $8, $9, $10}' "$f"
done > "${Pout}${output}"
echo "Finished Looping through each file."