I would say these are similar. I own 821 Chimére in the Dior Mono Fusion shadow, and Diapson in the Chanel Illusion d'Ombre shadows.
Honestly, I think that the Dior shadows are priced better (the Dior Mono Fusion shadows are $136/oz, while the Chanel Illusion d'Ombre shadows are $257/oz - that's nearly twice as expensive per ounce, although I'm not sure that the shelf life of these eyeshadows will let you make the most of that).
I like both eyeshadows a lot, and I often wear them together. I would say that for me, the main differences are that Diapson is a duochrome, and can be built up to full opacity (Chimére is not a fair shade to compare it against, but it does have less dimension, and swatching the other shades of the Dior Mono Fusion seemed like they often fell short of full opacity, although you could get quite deep colors with some).
I prefer the texture of the mono fusion immensely - the illusion d'ombre shadow felt much grittier to me. And I did experience fallout with the mono fusion eyeshadow, but not the illusion d'ombre. In terms of wear time and creasing, they seemed comparable (no noticeable creasing, and wore well for a full day).
chanel one is more giltter then this one, This one is like shimmer can use like base, chanel I think is better be a top
I have one of each, and they are more similar than different however the differences are noticeable. As someone before me said CD has more fine shimmers and is more of a wash of color/shimmer. The Diors you can wear over matte shadows to give some POP. On the other hand, the Chanels are more cream/mousse consistency. The Chanels would work well as a base you can layer powder shadows on top of. Both can be used alone.
Yes, very very similar. I own various colors in both Chanel and Dior's formulas, and they are almost identical, texture wise. Only difference is this one is $30, compared to Chanel's $36.
they are a bit different from the Chanel cream eyeshadows. These have more fine glitters than the Chanel's also the texture and consistency of the eyeshadows are different from Chanel's too. Also they weigh more and cost you less.