In an arena setting such as this, where the writing is inherently competitive in nature, writers are generally held to a higher standard of detail than they would be in non-competitive writing. Imagine how much more smoothly this entire exchange would be going if he details of his phasing ability had been outlined previously? Using details in your character sheets and posts is not a way of babying your opponents, it's a way of avoiding unnecessary OOC debates like the one we're engaged in right now. Not only did you fail to specify how the power worked, you also failed to give it even a single specific mention in your CS, apparently expecting us to infer that because your diety is a god of the multiverse his champion automatically possesses the ability to shift himself into a shadow universe of the one this RP takes place in. The only information we had was that Herriman "ceased", then un-ceased half a second later at the mid-point of mifune's leap. That's all. Everything else has to be assumed because you never once even outlined how the ability worked. 

To put it another way, how would you take it if you had an opponent who came in (and this opponent is already a good deal more powerful than your character) and started using a power that was never even mentioned in his CS? Then, when he doesn't like the way you countered his attack, he proceeds to elaborate on the details of his power, many of which remove your only advantages. Not only is he completely undetectable in this transition state, but he can still see you perfectly! And that's not all, because he's also now even faster than you are in this shadow world (rendering your only advantage completely moot) and can set up completely undodgeable attacks on a whim! 

Do you see where I'm coming from with this? Teleporting through alternate dimensions is one thing, but being able to shift there and remain completely untouchable and undetectable while taking your time to set up a perfect attack against an opponent who can never see it coming (especially when said opponent is normally a couple dozen times faster than you are) is quite another.