A Dark Eldar Archon has 3 attacks listed on his profile. He is equipped with an Agoniser and a Splinter Pistol. In a melee situation, does he get 2 attacks with the Agoniser and 1 with the pistol? Do you differentiate these attacks by rolling with different dice? Or does he holster the splinter pistol because the shooting phase has finished and just go ballistic with his whip hand, like an old Thundercat toy with an action arm lever?