Just like Kamen Rider Decade, Kamen Rider Diend will make his return to the series with an all new transformation device, the Neo Diend Driver. Like the original Diend Driver, it allows him to summon past Kamen Riders and if the Neo in the name is an indication, we might see him summon Riders that came after him. He will use these Riders to fight Kamen Rider Woz.
Kamen Rider Zi-O's 29th and 30th episodes will air on March 31st and April 7th respectively.
[Source: Natalie, Kamen Rider Zi-O Twitter]