Inkay evolves into Malamar starting at level 30, but only if it levels up while the game system is held upside down. Here are the key details for evolving Inkay:

• The system must be flipped upside down during the level-up.
• The console needs to be in handheld mode.
• First-party JoyCon controllers must be attached; third-party JoyCons and Pro Controllers are not supported.
• The console must be held straight upside down, not tilted or slanted.
• Inkay will evolve at the next level up past 30 when these conditions are met.
• Using Rare Candy to level up while upside down will also trigger evolution.

This evolution method is unique because it requires the physical orientation of the game console to trigger evolution, leveraging the Switch's gyroscope feature.