  This paper investigates the relationship between the hyperbolicity of complex
quasi-projective varieties $X$ and the (topological) fundamental group
$\pi_1(X)$ in the presence of a linear representation $\varrho: \pi_1(X) \to
{\rm GL}_N(\mathbb{C})$. We present our main results in three parts.
  Firstly, we show that if $\varrho$ is bigand the Zariski closure of
$\varrho(\pi_1(X))$ semisimple, then for any
$X^\sigma:=X\times_\sigma\mathbb{C}$ where $\sigma\in {\rm
Aut}(\mathbb{C}/\mathbb{Q})$, there exists a proper Zariski closed subset $Z
\subsetneqq X^\sigma$ such that any closed irreducible subvariety $V$ of
$X^\sigma$ not contained in $Z$ is of log general type, and any holomorphic map
from the punctured disk $\mathbb{D}^*$ to $X^\sigma$ with image not contained
in $Z$ does not have an essential singularity at the origin. In particular, all
entire curves in $X^\sigma$ lie on $Z$. We provide examples to illustrate the
optimality of this condition.
  Secondly, assuming that $\varrho$ is big and reductive, we prove the
generalized Green-Griffiths-Lang conjecture for $X^\sigma$. Furthermore, if
$\varrho$ is large, we show that the special subsets of $X^\sigma$ that capture
the non-hyperbolicity locus of $X^\sigma$ from different perspectives are
equal, and this subset is proper if and only if $X$ is of log general type.
  Lastly, we prove that if $X$ is a special quasi-projective manifold in the
sense of Campana or $h$-special, then $\varrho(\pi_1(X))$ is virtually
nilpotent. We provides examples to demonstrate that this result is sharp and
thus revise Campana's abelianity conjecture for smooth quasi-projective
varieties.
  To prove these theorems, we develop new features in non-abelian Hodge theory,
geometric group theory, and Nevanlinna theory. Some byproducts are obtained.
