thought to kill him by mischief —

 having mischief —

 deceit of coming in mother-s form —

 with mischief —

deceitful —

having deceit —

caused by (emperumān’s) deception —

came with mischief (assuming the motherly form) —

mischief —

which would, each on its own ability, cheat us out of the good place and push us into a corner. —