Examples of calculations
EDIT : The examples were taken again following the simplification of the first post

Defense
Attacker 1: Richard (Att=650)
Defender 1: Grimm (Def=600)
Calculated damage: 100x(650/600)^1.35=111  Damage found: 112
Attacker 2: Elena (Att=788)
Defender 2: Zeline (Def=619)
Calculated damage: 100x(788/619)^1.35=139  Damage found: 149 
Special Skills
Attacker: Zeline (Att=724x154%=1108, the capture dates from before the reduction of Zelineâ€™s special skill)
Defender 1: Richard (Def=783x120%=940, powerful attack)
Calculated damage: (100x(1108/940)^1.35)x2=250  Damage found: 212
Defender 2: Elena (Def=578x120%=694)
Calculated damage:100x(1108/694)^1.35=188  Damage found: 181
Defender 3: Kadilen (Def=734x120%=881)
Calculated damage: 100x(1108/881)^1.35=136  Damage found: 144
Defender 4: Domitia (Def=682x120%=818)
Calculated damage: 100x(1108/818)^1.35=151  Damage found: 163
Defender 5: Vivica (Def=699x120%=839)
Calculated damage: 100x(1108/839)^1.35=146  Damage found: 154 
Tiles (1 hero of the attack color)
Forward: Wu Kong (Att=834)
Defender: Kadilen (Def=734x120%=881)
Calculated damage: 1/3x100x(834/881)^1.35=31  Damage found: 35 & 35 & 33 
Tiles (2 heroes of the attack color)
Attackers: Kiril & Grimm (Att=(725 + 844)x1.1=1726)
Defender 1: Rigard (Def=733x120%=880)
Calculated damage: 1/3x100x(1726/880)^1.35=83  Damage found: 98
Defender 2: Little John (Def=642x120%=770, weak attack)
Calculated damage: (1/3x100x(1726/770)^1.35)/2=50  Damage found: 58
Defender 3: Gormek (Def=632x120%=758, powerful attack)
Calculated damage: (1/3x100x(1726/758)^1.35)x2=202  Damage found: 206 & 218 & 203