The HumanIK Controls give you finer control over the retargeting result between the FightSource and Character1 characters. These controls contain the IK Blend T, IK Blend R, and IK Pull sliders.
To adjust retargeted animation using the HumanIK sliders
Notice that Character1's right forearm is penetrating its body.
This problem can occur when discrepancies in size exist between your source and target characters. You can fix this undesirable retargeting result by adjusting the IK Blend T value.
The cell updates to give you visual feedback on the IK Blend T setting.
This adjustment makes Character1's right wrist reach toward the position of FightSource's right wrist, and away from its own body.