Of course, Jumbo Cactuar will have a big ol target on its spikey back as soon as it hits the battlefield, so its worth attaching indestructible or hexproof to it to prevent it from reaching an early grave
1 Chord of Calling promo and
Most players will be happy enough to use the Uncommon version
There are a couple of decent questers with high Willpower and high lore value in this deck, like Robin Hood, Daydreamer and Starkey, Devious Pirate, but more often than not you'll get more value out of steadily questing with an unanswered Don Karnage than you will with an intimidating late game bomb
Perhaps the coolest way is to pair Sin with cards that reliably exile unwanted cards from your graveyard at will
Hiram Flaversham, Toymaker, lets you exchange your items for card advantage