How does the Unchained's talent, 'Dissipate' stack with the Block Cost Reduction property?

//ads -- adsterra.com -- native banner
?>
The Unchained's level 20 talent, Dissipate is described in-game as:
Block cost is reduced by 50% when Overcharged and blocking attacks vent Overcharge.
How does this stack with the 'Block Cost Reduction' property in melee weapons and necklaces? e.g., If I already have 30% Block Cost Reduction from a necklace, how will this stack with Dissipate? What will my total block cost reduction be?
Pictures about "How does the Unchained's talent, 'Dissipate' stack with the Block Cost Reduction property?"



Yu-Gi-Oh! - Unchained Archetype
Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.
Images: Matthias Groeneveld, Karolina Grabowska, Ketut Subiyanto, Ryutaro Tsukata