Like you said, you make chains force him to spread his legs in the illusion. In turn, they do the same movement in reality. Say you make a strong human grab and restrict him from behind, the human may force his hands by diverting his own weapon against him in the illusion and thus the body can be fooled to undergo same movement and should the target have a sort of weapon on his hands, he could cut or impale himself.
You learned
( Doujutsu: Genjutsu Sharingan ) - Eye Technique: Copy
Wheel Eye Illusion
Rank: C - S
Type: Supplementary
Range: Short-Mid
Chakra cost: 15 - 40
Damage points: N/A
Description: This technique is simply the use of generic genjutsu used by members of the Uchiha clan. By simply having their opponents look into their eyes, the Uchiha can lock the user within a genjutsu of their choosing.
Note: Can only be used with 3 tomoe sharingan
Next
I put you in a A-rank Illusion where your hairs begin to grow rapidly and would begin to bind you. You eye lashes would grow and cover your eyes completely so you can't see.
So this is a simple illusion which you can not break with Kai. Also I don't want you to pierce through the illusion but I want you to analyse and detect you are in an illusion and then use your sharingan to reverse the effect of the illusion towards me. You would be releasing yourself also in the process.
( Bōshi Magen: Kyouten Chiten ) - Demonic Eye Illusion: Heaven And Earth Change
Type: Supplementary
Rank: C-S
Range: Short - Long
Chakra Cost: N/A (equal to the cost of the countered technique)
Damage Points: N/A (equal to the power of the countered technique)
Description: This is a illusion counter where, through the use of their sharingan, a Uchiha can take control over an enemy's Genjutsu and reverse it back into the opponent by taking control of it and releasing oneself at the same time. With 1 Tomoe, it can affect C-Rank and below illusions. With 2 Tomoe, it can affect B-Rank and below illusions. With a 3 Tomoe, it can affect A-Rank and below illusions. With MS, it can affect S-Rank and below illusions and EMS can affect any rank Genjutsu. Note: Can only be used once every two turns. Note: Does not require eye contact and must be able to cast
( I.e., cannot reverse a Sound Genjutsu without Sound Ninjutsu.