How does the cost reduction applied? (New interaction with Hemet, Jungle Hunter?)
So I've got all that knowledge that reads the following: Hemet will not destroy cards in the deck reduced to 0 mana cost by Barnabus the Stomper, if their base cost is 4 or greater.
This is likely because Hemet only looks at the base mana cost of cards in the deck, not modified costs.
Barnabus' own effect itself reduces the card cost to 0 if you draw a card, so each time you draw a card after Barnabus' battlecry, it's cost will be reduced to 0.
But I got stumpled upon a reddit thread which states that Hemet, Jungle Hunter will now remove all cards from your deck regardless of their costs: https://www.reddit.com/r/hearthstone/comments/6k09sm/fun_fact_playing_hemet_jungle_hunter_after_you/
Obviously, there is no proof by its author.