That seems incredibly naive. There are many examples of extremely intelligent people with psychopathy or narcissism. Also empathy does not lead to kindness by default; it is used as a tool by the most sadistic.

It is true that empathy is defined as ability to relate, and that doesn't imply happiness. Similar with intelligence. It's a quirk of our current reductionist world.

However, our definitions for those things are murky. I'm making a bold claim that being evil is ultimately a dumb move.

I'm also making a bold claim by estabilishing a path from intelligence to empathy to kindness. Actually, before intelligence, comes communication.

Communication -> Intelligence -> Empathy -> Kindness

In that sense, when empathy does not lead to kindness, it's because whoever has it stopped before moving to the next step.

The empath who is not kind stopped at an important step. He is able to relate to others, but is not able to observe higher dynamics except for when those dynamics include himself.

Maybe you're being naive about what kindness means. It seems that you are relating it to altruism and charity in a very superficial sense.