Blasphemous 2

This achievement requires the player character to deal more than 250 damage with a single strike.

I will preface this by saying that you will need to have Veredicto fully upgraded (or mostly upgraded), as well as all slots unlocked in the Altarpiece of Favours. Additionally, to accomplish this you will need the following figures equipped.

Group 1
The Anointed One (Page 1 - Candle)
The Thurifer (Page 1 - Candle)

Note - this is the only pair that must be together as it provides the Gregal's Favour resonance, which increases Veredicto's strength. If these are not paired you will be unable to break the 250 damage threshold. All other figures listed can be placed in any order.

Group 2
Castula (Page 5 - Circle)
The Purified One (Page 4 - Feather)

Group 3
The Thirst (Page 3 - Skull)
Tirso (Page 3 - Skull)

Group 4
The Unwavering One (Page 2 - Sword)
The Traitor (Page 5 - Circle)

With this set up, be sure you are free of guilt and travel to the left-most/west-most Prie Dieu in Grilles and Ruin as there are four hammer wielding enemies in this area that you can use for farming a crit.

Rest at the Prie Dieu, then use all of your bile flasks. Afterwards, use to activate Veridicto's ability Embers of Faith.

While Veredicto is covered in flames, go to each of the hammer wielding enemies and use a fully charged attack, Thunder of Mercy, on each of them. If you do not get a critical hit, rest at the Prie Dieu and repeat the process.

The achievement will pop as soon as an individual strike exceeds 250 damage.

For greater clarity on your damage output, go to settings (the furthest right tab in the pause menu), select game, and change Damage feedback to numbers. This will allow you to see the exact damage each strike is producing.