Ignition Phase (イグニッションフェイズ Igunisshon Feizu) is the fourth phase of a turn and also the last phase before Main Phase.
During this phase, the turn player may choose to perform Ignition or skip to the Main Phase. Certain Z/X has automatic abilities and effects that either has the timing of "at the beginning of the Ignition Phase" or only triggered if said Z/X appeared during Ignition Phase.
505 Ignition Phase
505.1 "At the beginning of the Ignition Phase" automatic event activates.
505.2 Perform the priority preprocessing (702).
505.3 The turn player is able to choose a card in his or her own Charge, or choose to pass.
505.3a If the turn player choose a card in Charge, he or she move that card into his or her own Trash, and reveal the topmost card of his or her own deck zone afterwards. If that card is a card with Ignition Icon, the turn player is able to play (803) that card immediately, without paying the Cost of that card. If that card is not played, or is a card without Ignition Icon, put that card into Trash.
505.4 Perform the priority preprocessing (702).
505.5 If the turn player chooses a card in Charge, return to 505.3. If the turn player choose to pass, proceed to the Main Phase.