Can a signature spell like Super Mega Death Rocket be placed in the chosen champion zone at game setup, or must it be a unit?

Ruling: Only a unit with the champion tag can be placed in the chosen champion zone at game setup. Signature spells always start in your main deck and must be drawn to be played.

Sequence:

• Your legend (non-unit card) goes in the legend zone and provides its ability throughout the game
• Your chosen champion (a unit with the champion tag matching your legend's character tag) goes in the chosen champion zone
• Your signature spell (matching your legend's character tag) starts in your main deck

Nuances:

• The signature spell cannot be placed in the chosen champion zone at game start
• Signature units (like Tibbers) also start in the main deck, not the chosen champion zone
• You can only have a signature spell/unit if it shares the same character tag as your legend