Ultimate Incursion title-Harley Quinn x Elvira which means the signatures were

which means the signatures were witnessed and authenticated by Valiant Comics themselves

and a choice of turret-mounted prow gun – a great sky cannon

as Douglas Wolk notes

a water caste spy

Ultimate Incursion title-Harley Quinn x Elvira which means the signatures wereThe Ultimate Universes first ever event series! Universes collide with Miles Morales caught in the middle! Before the Maker remade Earth 6160, he left Miles Morales the key to reach his new universe but when Miles baby sister, Billie, uses that key to travel to the Ultimate Universe, its up to Spider Man to save her! The problem is that the Ultimate Universe is never safe for any Spider Man! And when the Spot attacks, Miles meets an all new Peter