Some say "imaginary", others would say "imaginative", and thank you for the complement!
Speaking of which, Redcloak is showing an awful lot of creativity (cf. elementals). There are some who have underestimated his ability to solve problems, and they are mostly dead or worse (...Start of Darkness anyone?)
I misread, or was mislead by, a wiki somewhere. How could a wiki be mistaken?
---
Let me state for the record that the notion of RC handing Xykon a fake phylactery strikes me as absurd.
1. X has trusted RC with it all along, and nothing has changed his reasons for doing so.
2. RC has no way of knowing whether X has bugged the phylactery with something RC can't replicate in a fake.
3. The penalty for getting caught is extreme - not merely whatever death X chooses to deal however slowly X chooses to deal it, but also the collapse of the Dark One's plan.
4. The usefulness of fakery seems low. When RC wants to do something dirty with the phylactery, all he has to do is plan ahead a little bit, then Word Of Recall back to his sanctuary where he's secreted a Teleport thingamabob to whereever the phylactery-breaking-thingy may be.
Redcloak's plan is sure to have one element at least: it will be very very wise. Relying on X not to notice a fake phylactery seems unwise.