Digits!

$6535^{458} - 5867^{482}$ , we'll use Modular Arithmetic to find the unit digit.

$5^n$ where $n$ is any positive integer, its unit digit will result in a $5$

So $6535^{458} \equiv 5^{458} \equiv \boxed{5} \pmod{10}$

$5867^{482} \equiv 7^{482} \equiv 49^{241} \equiv 9^{241} \equiv (-1)^{240} * (-1) \equiv 1 * -1 \equiv \boxed{9} \pmod{10}$

$5-9 = -4$ , which implies $\color{#20A900}{\boxed{4}}$ is the last digit.