  This paper contains three new results. {\bf 1}.We introduce new notions of
projective crystalline representations and twisted periodic Higgs-de Rham
flows. These new notions generalize crystalline representations of \'etale
fundamental groups introduced in [7,10] and periodic Higgs-de Rham flows
introduced in [19]. We establish an equivalence between the categories of
projective crystalline representations and twisted periodic Higgs-de Rham flows
via the category of twisted Fontaine-Faltings module which is also introduced
in this paper. {\bf 2.}We study the base change of these objects over very
ramified valuation rings and show that a stable periodic Higgs bundle gives
rise to a geometrically absolutely irreducible crystalline representation. {\bf
3.} We investigate the dynamic of self-maps induced by the Higgs-de Rham flow
on the moduli spaces of rank-2 stable Higgs bundles of degree 1 on
$\mathbb{P}^1$ with logarithmic structure on marked points
$D:=\{x_1,\,...,x_n\}$ for $n\geq 4$ and construct infinitely many
geometrically absolutely irreducible $\mathrm{PGL_2}(\mathbb
Z_p^{\mathrm{ur}})$-crystalline representations of
$\pi_1^\text{et}(\mathbb{P}^1_{{\mathbb{Q}}_p^\text{ur}}\setminus D)$. We find
an explicit formula of the self-map for the case $\{0,\,1,\,\infty,\,\lambda\}$
and conjecture that a Higgs bundle is periodic if and only if the zero of the
Higgs field is the image of a torsion point in the associated elliptic curve
$\mathcal{C}_\lambda$ defined by $ y^2=x(x-1)(x-\lambda)$ with the order
coprime to $p$.
