A frequent commissioner of mine really wanted to see Mark Grayson enduring tickling during a training session. No bondage involved, the challenge here is to keep up his strength while his feet and armpits are tickled. He's managing to hold up the immense weight of the training device, but with Omni-Man delicately stroking his pits and mechanical hands fiendishly dancing on his soles he can't help but laugh. Turns out he's not so Invincible after all...