tachiyomi/app/src/main/res/drawable/unread_angled_badge.xml

<?xml version="1.0" encoding="utf-8"?>
<vector xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:width="100dp"
    android:height="100dp"
    android:viewportHeight="10"
    android:viewportWidth="100"
    tools:background="@color/red_error">

    <path
        android:fillColor="@color/unread_badge"
        android:pathData="M0 20 L100 0 L100 20 Z"
        android:strokeColor="@color/unread_badge" />

</vector>