Note: “CP” = Card Power
I’ve worked out the exact CP formula.
Each card has a base CP when stats are all 0. That value is:
1* Base CP: 0
2* Base CP: 10
3* Base CP: 30
4* Base CP: 50
5* Base CP: 90
Specials are worth 5 extra CP for each level after the first
Talent tree nodes are worth a flat 5 CP each, and stat increases from talent tree nodes don’t have a direct effect on CP (so whether the node gives you 15 Attack or 45 Attack, it’s still 5 CP). See the discussion in posts below for the details.
The Full Formula
CP=(base CP for stars) + floor(attack * 0.35 + defense * 0.28 + health * 0.14) + (special level - 1) * 5 + (Talent tree nodes) * 5
Examples:
Marjana at 4/80 special 8:
A: 669 D: 712 H:1404
floor(669*0.35+712*0.28+1404*0.14)=630
CP(calc)=90+630+35=755
True CP: 755
Gobbler at 1/1 special 1:
A:347 D:212 H:613
floor(347*0.35+212*0.28+613*0.14)=266
CP(calc)=50+266=316
True CP: 316
Hawkmoon at 3/41 special 8:
A:459 D:432 H:618
floor(459*0.35+432*0.28+618*0.14)=368
CP(calc)=30+368+35=433
True CP: 433
Tiburtus at 3/60 special 8:
A:548 D:525 H:868
floor(548*0.35+525*0.28+868*0.14)=460
CP(calc)=50+460+35=545
True CP: 545
Onatel at 4/10 special 8:
A:534 D:704 H:1242
floor(534*0.35+704*0.28+1242*0.14)=557
CP(calc)=90+557+35=682
True CP: 682