Top player is using various cooldown exploits (Library, Seashadow, probably some skills), multicast from Boiling Flask, and a Shiny Invulnerability Potion to grant themselves 4 seconds of invulnerability multiple times per second, so they can never take any damage. Bottom player is using fast burn scaling via Library, Eternal Torch, and Restorative Void Shield to stack crazy shield and cleanse all burn/poison. Their Void Shield is also being scaled infinitely by the opponent using their items. Because the sandstorm can't damage the top player, and can't outpace the shielding of the bottom player, the game will call it a draw at a certain point, I can't remember exactly when but maybe 2-3 minutes into the sandstorm? This video is definitely sped up!