When entering a battle stage, the player is able to choose up to either 5, 6, or 7 out of 12 Sinners (Dante not included) to fight. Each Sinner can be equipped with an Identity that defines their base skills, and a set of powerful E.G.O skills. Each E.G.O skill has an assigned power level, and a Sinner may only equip one of each. Newer stages using the Chain Battle format allow the player to substitute backup Sinners in when an on-field Sinner dies, effectively allowing the player to use all 12 Sinners. In normal unfocused fights, the player drags a pointer across two rows of icons. Each icon represents one of a Sinner's skills. The aim is to form a chain of attacks against enemies. In focused fights against Abnormalities or bosses, players instead will be directed to pick and choose which Sinner's attack should target which enemy, or a specific body part of the enemy. Matching attacks of the same color, or Sin Affinity, activates Resonance, which increases the damage of the attacks included. Using a skill also yields "Sin Resources" of that attack's Sin Affinity. Attacks are also classified into different damage types: Slash, Blunt, or Pierce. Different enemies are resistant, neutral, or weak to different damage types. Finally, every skill has an attack weight behind it, determining how many enemies it will hit. Skills with more than 1 attack weight may deal a fixed amount of damage to all targets, or hit targets randomly a certain number of times. When a Sinner and enemy clash, the game decides which side's attack is successful with a series of coin flips, with Sanity Points (SP) determining a character's luck in flipping heads. A head will alter to the skill's base power by the coin power (typically an increase; a decrease instead for certain Identities and E.G.Os), while a tail leaves the final power as is. When one side has a higher power, they win the clash, the loser loses one of their coins, and the coins are re-flipped. This process continues until either side loses all their coins, after which the winner launches their attack. Some characters' skills may also have unbreakable coins, colored in red. As per their name, unbreakable coins will not break even if that coin flip was lost (their coin power will not count in future flips), and allow a character to attack even if they lost the clash. Unbreakable coins that lose clashes will become "cracked," setting their coin power to +1. Moreover, some enemies' attacks have Excision coins, colored in green. These coins can destroy unbreakable coins in a clash, and act like an unbreakable coin when losing a clash. At the start of each turn, each Sinner rolls a random speed value within a defined range. A Sinner may attack, or clash with, any enemy with lower speed than them, and can only attack enemies as fast as, or faster than, them, unopposed. However, a Sinner may also clash with any enemy that directly targets them. The player can choose to attack using a Sinner's E.G.O. skill in place of one of their normal skill. E.G.O skills are often significantly more powerful than a sinner's normal skills; however, doing so spends the Sinner's SP and a number of collected Sin resources. The lower a Sinner's sanity is when they use an E.G.O. skill, the higher chance they have to launch a "corroded" E.G.O. skill, which is more powerful, but renders that Sinner uncontrollable and prone to attacking allies for one turn. The player can also use a corroded E.G.O. skill without the risk of harming allies by "Overclocking" the E.G.O. skill, unleashing its corroded variant, but at the cost of additional Sin resources and SP. The player may also choose to replace a Sinner's skill with their respective defense skill, of which there are three types. Guard skills generate a shield that resists a certain amount of damage, Evade skills dodge attacks whose power are lower than or equal to the evasion's power, and Counter skills unavoidably attack an enemy after the Sinner is attacked (unless the Sinner is Staggered before activating the counter). Some Counter skills are clashable, meaning they can clash with an enemy's attack and halt it entirely. When a character's health falls below a certain limit (which is different for every enemy and Sinner), they become Staggered, greatly increasing the damage they take and preventing them from acting next turn. most Identities and several enemies have multiple Stagger Thresholds that allow them to be Staggered repeatedly, amplifying the effects each time.
Gacha system Identities and E.G.O. can be unlocked using the game's gacha system, called "Extractions". Extractions can be performed using "Lunacy", a currency obtained from clearing stages, clearing the weekly "Mirror Dungeon" game mode, or from
in-app purchases, or "Extraction Tickets", which can be obtained from the
battle pass and various events. Alternatively, "Egoshards" for the different Sinners can be spent at the "Dispenser" to purchase identities and E.G.O. directly. Egoshards can be obtained through Extractions, opening , or through Egoshard Crates obtained from the battle pass. Most Identities and E.G.O. are permanently available; however some are only obtainable during
Walpurgisnacht events that occur every few months, while Identities and E.G.O from the previous season cannot be obtained using Egoshards until the next season. ==Setting==