Codewords:

         Kid Ying   Dr. Yang
Level 1: ZXZZkz     K4HjVJ
Level 2: h8HXXX     2+PLQH
Level 3: jk232      2+2HQH
Level 4: 7GRvov     +ZK696
Level 5: XTtttw     TXrZyZ
Level 6: Z+nHTH     TXrZyZ
Level 7: 33t8G8     RMTYyY
Level 8: 4Kmy7y     MRDj1j
Level 9: JPP2msm    RMdVsY

Codewords by Arne Beilschmidt - Beilschmidt@T-Online.de