For what we know Nova Grappler has Raizers, Beast Deities, Extreme Battlers, Death Armys And more. Let me tell you if there is a series that making your unti powerful by Resting itself and get power/critical/new abillity.
Nova Grappler from the Nation Star Gate which is Cray Southern Pole, which means its cold. How about a Junk Robot Series? Focused on Resting Itself. These unit can mix with Raizers, Extreme Battlers and Beast Deities.
One card maybe like this Name : Junker Army, Gaze Double Crit : 1 Grade : 3 Pow : 8000 Race : Junkroid Skill : [Auto][VG]GB4 & Rest This unit | Choose 4 of your units and it gets "[Cont]: This unit cannot be attacked" and "[Cont]:This unit gets 8000 Power for Each card in your Drop Zone"
First : Why Dropzone? Because the series is Junk Robots Second : Why Getting Powers? Spare Parts And Mechanism