A Perfect Attack is when all squares were used, and in almost all situations should be done no matter what. Auto attacks (including by PvP opponents) always does a Perfect Attack (although not always the best possible one). The better the biggest chain done in a turn, the better the combo attack.
Although a 5/4 chain combo attack can be very strong (especially against a boss / when using a hero with a "chain" passive, especially since chains by default boost attack as well), it's sometimes better to purposefully get the 3-chain Perfect Attack, since sometimes killing 1 opponent and damaging all other by ~25% isn't nearly as good as damaging all by ~50% (this is more often the case when not facing a boss).
Each hit of a Perfect Attack has a chance to be a critical based on your team's critical rate.
- 5 chain - Single - Heaven's Fall - Launches single enemy into the air and all your heroes smash into it from Heaven.
- 4 chain - Single - Gravity - Multiple attacks to one enemy delivered by all heroes.
- 3 chain - AoE - Mini-me Rush / Mini-me Assult - Send a bunch of mini version of your heroes stomping all opponents; the more opponents, the less effective this is against each one. This can be targeted on a single enemy if need be.
- 2 chain - AoE - Justice Thunder / Cross Thunder - Weakly hits all targets
- 1 chain - AoE - Dragon Stomp - Weakly hits all targets