Arsenic > Long Sword. Poison against your opponent is so good you can't pass it up. Long Sword is only more powerful than upgraded Arsenic for the first two attacks. Attack 3, they're even, and Attack 4 onwards, Arsenic is more damage. Yes, it does cost ONE more quanta, but honestly...? Not a problem in this deck.
I agree with mummies being bad. However, Deadly Poison with Shards of Bravery.... o_0 YES DO IT