I'm offering the same preface I did to my other omnibus reviews: Writing reviews for xxxHolic is a futile sort of thing, because it's a story that, in all honesty, is greater than the sum of its parts, which I do actually mean in the best way I can. It's just, the gut punch that is this series requires the build up, requires the many moving pieces slowly fitting into a solid machine of grief and longing and bento boxes (and by many moving pieces, I don't mean the plot events related in Tsubasa--those are the number one reason I never authentically recommend this series for others, as it makes no gotdamn sense thanks to the the Tsubasa crossover arc). Also, reviewing is difficult, as I am completely unable to be objective about this series. So what's going to happen is I'm going give a rough review of what happens in each omnibus and how much pain it's going to cause, strictly so I can remind myself later when I'm trying to remember what events happen where. As such, spoilers abound.
Omnibus #2 contains volumes #4-6. Shit's starting to get LIT y'all. With these volumes we get the ICONIQUE Valentine's Day Chocolate Debacle in which Doumeki's soul is inexplicably tied up in Watanuki's cake. We also get one of my all time favorite story episodes with the twins. And some Watanuki spirit pain in the form of a childhood friend. And that's just the first volume, Jesus. We also get the ICONIQUE incident with the hydrangea, some more episodic character stuff, the ICONIQUE Hyakki Yako, and some more sad Watanuki spirit stuff. I think what this omnibus does is really start solidifying the deft with which xxxHolic handles issues of choice and self-determination. This is the point where we start seeing serious truths about humanity spoken in between the silliness and sweets. This omnibus is going to lay a foundation of pain that you will not be getting relief from! So that's fun!