pests

Just dipped some corals and found these saved them from dying, but do not want them in my tank unless they help

Was dipping a coral frag disc and this was chillin on it. It's very small about 5mm. The closest thing I can find is a chiton but no patterns match. Any clue on what this is?

So I've been doing some reading and bought a 5.5 watt cnc engraving laser to nuke pests in my tank. Currently it's little star fish but most accounts are about aptasia. I also wanted a plug in version since the batteries don't last long. One I've got comes with a beefy heat sink and I added a...