Test your knowledge of Heroes of Might and Magic III.

It all depends on the damage dealt. Let's assume that both sides deal their maximum damage. That is, the Sultan deals 24, and the Archdevil deals 40.
The devils will attack first, as they have higher speed. The difference in attack and defense is 26-14 = 12 units. Therefore, the damage dealt by one Archdevil will be 40 + 12*0.05*40 = 64. Two Archdevils will deal 128 damage, which will undoubtedly kill one of the Sultan's Efreet, as it has only 90 health. There will be 6 and 1/52 health remaining. The Archdevils will take 20% of their own damage immediately due to the fire shield. That is, 26 units. There will be 1 and 1/174 health remaining. Next, the sequence of moves:

1. Sultans. (24 + (16-28)*0.025*24)*7 = 117.6; 1 Archdevil + 1 with 56 health.
2. Counterattack. Still 128; 6 Sultans + 1 with 18 health.
3. Fire shield 26. 1 Archdevil + 1 with 30 health.
4. Archdevils. 128; 4 Sultans + 1 with 70 health.
5. Fire shield 26. 1 Archdevil + 1 with 4 health.
6. Sultans 84; 1 Archdevil with 120 health.
7. Counterattack 64; 4 Sultans + 1 with 6 health.
8. Fire shield 13; 1 Archdevil with 107 health.
9. Archdevils 64; 3 Sultans + 1 with 32 health.
10. Fire shield 13; 1 Archdevil with 94 health.
11. Sultans 67; 1 Archdevil with 27 health.
12. Counterattack 64; 2 Sultans + 1 with 58 health.
13. Fire shield 13; 1 Archdevil with 14 health.
14. Archdevil 64; 1 Sultan + 1 with 84 health.
15. Fire shield 13; 1 Archdevil with 1 health.
16. Sultans 34; 0 Archdevils.

Remaining: 2 Sultan Efreet.