Step 1
Darmanitan used Ice Punch! (-6 EN)
Crit (1, d24): 14 (No), Frost (1, d10): 8 (No)
(8 + 3 + (20 - 7))*2 = 48
Darmanitan was hurt by Garchomp's Rough Skin! (-10 HP)
Garchomp used Swagger!
Miss (18 - 20, d20): 16 (No)
Darmanitan's Attack sharply rose! (+2 Atk, next 3 turns)
Darmanitan became confused! (Confusion, next 1 turn)
Step 2
Darmanitan used Ice Punch! (-6 EN)
Crit (1, d24): 14 (No), Frost (1, d10): 6 (No)
(8 + 3 + (20 - 7))*2 + (2 - 0)*4 => 51
Darmanitan was hurt by Garchomp's Rough Skin! (-10 HP)
Darmanitan hurt itself in its confusion! (-26 HP)
(Darmanitan's Confusion wore off)
Garchomp used Iron Head!
Crit (1, d24): 2 (No), Flinch (No)
(8 + (9 - 4))*1.5 => 20
Round Summary

HP: -10-10-26-20 = -66

EN: -6-6 = -12

EP: -48-51 = -99