Here's my best estimation for the max base ATK for raider cards during the Captain America vs Red Skull event. Bear in mind that alignment bonuses and player-based ATK power bonuses would be added to these base numbers.
- [Star-Spangled Avenger Captain America] - 1,200% / 2,600%
- Unfused Max ATK = 8,717 * 12 = 104,604
- Fused Max ATK = 12,204 * 26 = 317,304
- [Knight Vigilante Moon Knight] - 1,100% / 2,400%
- Unfused Max ATK = 7,590 * 11 = 83,490
- Fused Max ATK = 10,626 * 24 = 255,024
- [Plasma Sculpture First Human Torch] - 800% / 1,800%
- Unfused Max ATK = 7,038 * 8 = 56,304
- Fused Max ATK = 9,854 * 18 = 177,372
- [Overflight Falcon] - 400% / 1,000%
- Unfused Max ATK = 5,693 * 4 = 22,772
- Fused Max ATK = 7,971 * 10 = 79,710
- [Neighborhood Watchman Luke Cage] - 200% / 500%
- Unfused Max ATK = 4,117 * 2 = 8,234
- Fused Max ATK = 5764 * 5 = 28,820
- [All-Father Odin] - 170% / 350%
- Unfused Max ATK = 5,977 * 1.7 = 10,161
- Fused Max ATK = 8,340 * 3.5 = 29,190
- [Offspring Carnage] - 120% / 250%
- Unfused Max ATK = 4,945 * 1.2 = 5,934
- Fused Max ATK = 6,924 * 2.5 = 17,310
- Bucky Barnes - 130% / 160%
- Unfused Max ATK = 4,393 * 1.3 = 5,711
- Fused Max ATK = 6,152 * 1.6 = 9,843
- Maria Hill - 120% / 140%
- Unfused Max ATK = 4,301 * 1.2 = 5,161
- Fused Max ATK = 6,023 * 1.4 = 8,432