You can promote your characters via the ‘Promote Characters’ Machine, which can be found in Mike’s Basement.
Each Promotion will require an additional (one or two) copies of either the exact matching character or another character of the same color. Be aware that Promotions will also need these copies to be of a certain rarity.
If unsure of the Promotion requirements for a certain character, you can select it in the Character Promotion screen and the Game will indicate the necessary copies.
Please note that the copies -so the components -used for Character Promotion will be consumed and will therefore no longer be available on your account!
To promote a character, first select the (base) character, so the character you wish to promote, and then afterwards select the copies (components) you wish to use for this promotion. Once you have done so, simply click on the green “Promote” button, to complete the promotion.The order in which you click on the characters during Promotion is crucial to determine which character will be promoted (used as base) and which ones will be consumed (used as components).
To avoid accidentally using characters as components, always pay attention to the order in which you select the characters. The character displayed at the left will be promoted, the character(s) to the right will be consumed.
If you are unsure of how to promote a specific character, tap on the info button in the Character Promotion screen and the game will show you a breakdown of how to promote per character rarity level.