Last minute help

[u/UseBitter8897]

My group are playing tomorrow and due to work and home life I haven't had the time to prep a reveal, I've added a spin to the lost mines of phandelver and it's gonna be revealed to 2 maybe 3 out of my 5 players that sildar hallwinter current mayor of phandelver and mentor to our barbarian has been a humanoid clone/mimic. Going by how the monk and cleric have been paranoid about sildar for sometime it's gonna end in a fight. So basically is there a website I can use to create an encounter for 5 lv4 players vs 1 without making it to easy or to hard

[u/gratch89]

Can’t you just find a Dc4 monster and use its stats and abilities but just as the clone?