Thanee said:And where did you get that "if you do not have a psicrystal" part from?
By indirect implication of the rest of the text.
There is no place in the psionic rules that states or talks about the fact that a character can have multiple psicrystals. All discussions of a psicrystal are singular.
For example, under Metamind, the Cognizance Psicrystal special ability discusses the Metamind storing PP "in his psicrystal", not "in his psicrystals".
In Improved PsiCrystal, "You can implant another personality fragment in your psicrystal", not "You can implant another personality fragment in your psicrystals".
So, there are a few implications here:
1) Like all feats, just because you could lose the ability to use the benefits of the feat at some point in time does not mean that you will always lose the ability to use the benefits of the feat. There are typically ways to reacquire any lost feat benefits.
2) The feat only allows you to have one psicrystal (as per the implications in the rest of the text) and you cannot gain a second psicrystal at the same time because feats do not stack (i.e. you cannot take the feat multiple times to gain multiple psicrystals).
3) There is no section on permanent loss of a psicrystal. Like familiars, the implication is that if you lose one, you can replace one. They are merely constucts after all and it should be easy to replace a construct that you created once before. You shouldn't lose the knowledge on how to create one.
Is this all clearly spelled out in the rules? No. But, the implication is fairly clear.
Looking beyond this (i.e. "it does not say that, so it does not imply that") is mostly just rules lawyering and does not seem to be what most reasonable DMs would adjudicate (IMO).