The whole Eurozone problem is that each Eurozone country was issuing bonds in what was effectively a foreign currency, and so it lacked an effective lender of last resort.
Each Terra can be turned in for the specified share of the basket of commodities, which would be held as 100% backing of the currency, under contract with producers of those commodities who are partners in the financial institution issuing the Terras.
When the claim checks outstanding grow sufficiently numerous and when the issuing party can unilaterally determine their purchasing power, the pressure on the issuer to dilute their value by inflating the currency becomes almost irresistible.