Helloween have announced that they will be joined by former members Michael Kiskse and Kai Hansen on their 2017-2018 world tour, which they are calling “Pumpkins United.” They will perform with the band’s current lineup, Michael Weikath, Markus Grosskopf, Andi Deris, Sascha Gerstner, and Dani Löble, who are planning three hour sets composed of tracks…