If x in (-oo, -1) then as n->oo, abs(x^n)->oo monotonically, but alternates between positive and negative values. x^n does not have a limit as n->oo.
If x = -1 then as n->oo, x^n alternates between +-1. So again, x^n does not have a limit as n->oo.
If x in (-1, 0) then lim_(n->oo) x^n = 0. The value of x^n alternates between positive and negative values but abs(x^n) -> 0 is monotonically decreasing.
If x = 0 then lim_(n->oo) x^n = 0. The value of x^n is constant 0 (at least for n > 0).
If x in (0, 1) then lim_(n->oo) x^n = 0 The value of x^n is positive and x^n -> 0 monotonically as n->oo.
If x = 1 then lim_(n->oo) x^n = 1. The value of x^n is constant 1.
If x in (1, oo) then as n->oo, then x^n is positive and x^n->oo monotonically. x^n does not have a limit as n->oo.