Mulligans
With this OTK, you will be utilizing Sunsapper Lynessa In order to cast Holy Wrath Twice. You do this by reducing Holy Wrath to 2 or even 1 mana which can be done by using Sea Shill and Holy Cowboy. This combo can deal a maximum of 47 damage (Shirvallah, the Tiger + Molten Giant) with the minimum ceiling of 40 (2x Playhouse Giant). You could utilize Sir Finley, Sea Guide to shuffle the bigger minions to the bottom of your deck as well which always helps securing the maximum damage. A lot of the other cards within the deck such as Whack-A-Gnoll, Enter the Coliseum and, Prismatic Beam are some tools that can be utilized to stave off aggressive decks from devouring your hero.
I forgot to mention Cariel is also included in order to reduce Holy Wrath even further.