Secondary Arms

As a bonus action, you can sprout a second set of arms beneath the original pair. These arms can function the same as the originals, able to cast or operate on their own if the originals are inoperable.

If you didn’t have a second attack before, you gain a second attack action. In addition, you can use this with Flurry of Blows if you’re a monk, doubling the possible hits with said blows.