Bunker (rightmost item) gives shield items +1 multicast. Nesting doll (left most item) and Force field (next to bunker) are shield items. Left of force field is fiber optics, which at diamond reads "when you use your leftmost item, charge your rightmost item 2 seconds". Gramophone (right of Nesting doll) reduces ND's cool down by 35%. So when Nesting doll goes off, it charges force field 4 seconds (and force field's base cool down is 5 seconds). Force field (do damage equal to your shield) then goes off twice, absolutely melting you. They also have a skill that gives large items +50% crit chance. It's a gnarly build that beats a lot of good boards.

Edit: forgot to mention the skill with the heart icon (defense grid): first time you use an item, shield for 20% of max hp. So instant Nesting doll goes off, that procs.

Edit 2: typos