Renascent Chronicles 10 card pack bundles are available in the Shop for 1000 crystals each from the release of v3.4.12 until 8:00 a.m., August 4 (PT). The tenth pack has a guaranteed legendary card. Plus, you will receive 20 Renascent Chronicles card pack points for each bundle purchased.
Renascent Chronicle 10 card pack bundles can be purchased from Shop > Buy Cards > Buy Packs. They can be purchased up to 3 times per account. Draw rates can be checked from the card pack purchase screen.