Board Thread:Theories and Speculation/@comment-31338621-20200901181802/@comment-26636534-20200903204028

Well, Itachi's use on both Kakashi and Sasuke shows that there are two main ways for Tsukuyomi to manifest, overtly and deceptively. In Kakashi's case, Tsukuyomi was used overtly, as Itachi made no secret of time dilation while Kakashi was tortured. In Sasuke's case, Itachi used Tsukuyomi deceptively, seemingly not even attempting time dilation. It's unknown if using a deceptive Tsukuyomi would require Itachi to not use time dilation.

@BrainBrand, I'm not sure if I fully understand your scenario correctly, however, I doubt Tsukuyomi used overtly or deceptively, can be used while Itachi is simultaneously in combat.