Grand Cross combines ATK and MATK, applies its Holy element twice, hits three times, and hurts the caster — how each half is computed.
wave = Holy × (Holy × ATK half + Holy × MATK half) × (100 + 40 × rank)%
Delivered as three waves that are summed. Because both ATK and MATK feed the same number, a Grand Cross Crusader invests in STR and INT rather than choosing.
Each half is multiplied by the Holy element on its own, and then the sum is multiplied by it again before the skill ratio. Against a Dark 4 or Undead 4 target, where Holy does 200%, the two halves effectively take 400%. Against a Neutral target the element does nothing either time. This is why Grand Cross is so much stronger against Dark and Undead monsters than a single element multiplier would suggest.
It is also why every point of flat ATK is worth so much: a player measured Blade Mastery's +40 ATK adding 800 to each wave against a Loli Ruri (Dark 4): 40 × 2 × 2 × 5.
The physical half is an ordinary weapon hit: your weapon's size penalty, then the target's hard and soft DEF, then refine and mastery ATK. The magic half takes the target's hard MDEF and then its soft MDEF, exactly like a spell. Both are reduced before the element and the skill ratio are applied.
That means Provoke helps, because cutting the target's DEF scales the physical half. High-MDEF targets also blunt an INT-heavy Grand Cross noticeably.
Grand Cross hurts you too, in two parts:
Faith reduces both: its Holy resistance cuts the damage-based half (up to −50% at Lv10) and its +MaxHP raises the pool the 20% is taken from. The calculator shows the recoil as its own red panel rather than folding it into your damage.
No. The physical half takes hard and soft DEF like a normal weapon hit, and the magic half takes hard and soft MDEF like a spell. Reducing a target's DEF with Provoke therefore does increase Grand Cross damage.
Two parts: the hit recalculated against your own defences and Holy resistance then halved, plus a flat 20% of your current HP. Faith reduces both, through Holy resistance and extra Max HP.
Both. The damage adds ATK and MATK together before the skill multiplier, so STR and INT contribute to the same number, with VIT for survivability and the recoil.
The calculator prints every step of this with your stats, gear and target, so you can check the numbers rather than take them on trust.
Builds this affects most: Crusader — Grand Cross (GC).
Payon Stories wiki — Grand Cross ↗ · RateMyServer skill database ↗ · Formulas as implemented in the calculator's engine, which is open about what it cannot yet model.
How damage is calculated on Payon Stories · The weapon size penalty, and Weapon Perfection · All mechanics · Build guides