Is Chara actually evil?

So, I have been a huge fan of Undertale and have done some digging. I have seen in many places that Chara is shown to be evil and genocidal. Is this actually true? Can you please tell me? Thanks in advance.

Whether or not they (Chara) were evil or genocidal prior to the Genocide route I do not believe can be genuinely proven. However, their actions at the end of the Genocide route strongly suggest they are genocidal and are evil.

The definition of genocidal is "relating to or involving the deliberate killing of a large group of people of a particular nation or ethnic group." This is very deliberate; even if you state to not erase the universe, they proceed to do so anyways. This meets the definition of genocidal and goes well beyond it by killing all groups of people (and monsters) by destroying the universe instead of just one major group.

The definition of evil is "profoundly immoral and wicked." Destroying the universe and killing everyone with it (everyone but yourself and Frisk technically) is obviously profoundly immoral and wicked. The only way to restore the universe is to sell your soul; taking someone's soul is also evil.