Since you have 2 mixers, and essentially, you want to get more channels, hence you have two mixers..
You can use one mixer as a submixer.
Basically, mixer A (band) & mixer B (Drama/emcee/vox)
Depending how many channels you have on mixer A, leave 2 free channels on mixer A so that you can route the master output (L and R) of mixer B to the two free channels on mixer A. Like this u have a stereo submix of your vocals in that 2 channels.. and from Mixer A, you can send your vocal submix and band mix together on ur various aux sends.