Tyranny
Outrage, Atrocity, Cruel
noun, な adjective
Violence and oppression are all signs of tyranny and that someone is being really cruel.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
あいつらは暴虐の限りを尽くしたんだ。
They committed all kinds of tyrannical acts.
An update is needed before you can continue but you have more than one WaniKani tab open.
Finish up what ever you are doing on the other tab(s), then close them to continue.
The update will complete automatically once the other tab(s) are closed.