Questions in DONTFORGET

Hello guys, I was doing no mercy run okay, and I accidentally spared 1 monster does that ruin the whole game? Do I have to reset and try again? I am already like lv18 with 1 spare and alot of kills.
HELLO EVERY ! IM HERE BECAUSE I WANT TO KNOW IF I CAN USE [[2,00]] PARTNERS AT THE SAME TIME?????
Is there any way to transfer my progress on online mode from one account to the other? I'm asking becaus it's (as far as i know) it's impossible to change your name and I don't want to lose all my progress ;-;
okay, so i make an account, the game crashes, i try to make it again, it says email is alreayd in use, so i try to log in with the account info, it doesnt let me in when i type the password, just infinitley says "Loggin in..." or "Registering..."