  Building on the embedding of an $n$-abelian category $\mathscr{M}$ into an
abelian category $\mathcal{A}$ as an $n$-cluster-tilting subcategory of
$\mathcal{A}$, in this paper we relate the $n$-torsion classes of $\mathscr{M}$
with the torsion classes of $\mathcal{A}$. Indeed, we show that every
$n$-torsion class in $\mathscr{M}$ is given by the intersection of a torsion
class in $\mathcal{A}$ with $\mathscr{M}$. Moreover, we show that every chain
of $n$-torsion classes in the $n$-abelian category $\mathscr{M}$ induces a
Harder-Narasimhan filtration for every object of $\mathscr{M}$. We use the
relation between $\mathscr{M}$ and $\mathcal{A}$ to show that every
Harder-Narasimhan filtration induced by a chain of $n$-torsion classes in
$\mathscr{M}$ can be induced by a chain of torsion classes in $\mathcal{A}$.
Furthermore, we show that $n$-torsion classes are preserved by Galois covering
functors, thus we provide a way to systematically construct new (chains of)
$n$-torsion classes.
