YongnuoYN-622C WIRELESS TTL FLASH TRIGGER TRANSCEIVER FOR CANON

Do i simply need this pair to fire a single 430exii flash wirelessly from my 5dmk2? or do i need a transmitter also?

I have put in batteries and turned the switch to either of the two modes but no lights are flashing or on. Am I missing something?

Will it work on sony a7 ii and sony hvl 43m flash with mi shoe?

I put 1 yn622 + st-e2 in the shoe I'm going to work with two masters? What is your experience with this configuration? Af assistence