Here are some options that capture the meaning:
* "Calon Dechreuol" - This translates literally to "Beginning Heart," which evokes the idea of courage and boldness.
* "Calon Cwt" - This translates to "Strong Heart," which emphasizes bravery and resilience.
* "Calon Ddewr" - This means "Brave Heart," but it sounds a bit more literal and direct.
* "Cymro Dechreuol" - This means "Brave Welshman," which highlights the bravery of the Welsh people.
Ultimately, the best Welsh phrase would depend on the context and the specific nuance you want to express.