Hearthpwn

hard mulligan for Witchwood Piper and Reno Jackson (it provides 66% chance for reno turn 6).

mulligan for Shadow Council, Jepetto Joybuzz, The Dark Portal

You are seeking to perform such powerful turn, that your opponent simply fall from chair and lost internet connection.

The best powerplays are clearing bord with putting some shit on it, with emoting "You face Jarraxxus!"

My general recommendation:
without coin, you should tap on turn 2 and play shadow council on turn 3.
With coin, you should play shadow council on turn 2.

How to read below table

(use ctrl + "+" to get 125% view in webbrowser)

Color red example:
You played shadow council on turn 1. You have 0 mana.
You start turn 2 with 2 mana and 3 random demons.
On turn 2 you have 64% chance that at least 1 demonis cheaper than 3 mana.
You were lucky, you played demon. On turn 3 you still have 2 random demons and there is 72% chance that you can play at least one of them.
On turn 4 your last random demon has 64% chance to be played.
Unfortunatelly all 3 events together have only 30% to happen. (not to mention that having specific card on turn 1 is also not common).

Blue color:

You played shadow council on turn 2. You have 1 mana.
you have 6 random demons and there 59% chance that you can play one immidietally. 

So there is 50 chance % that you played random demon every turn since seond turn and 85% chane to play every turn since third turn.

General rule: do not put minions cheaper than 7 mana.

Below similar deck, but with more board presence,without OTK potential.