I think you maybe easing too much. You need to make it so that he quickly bends down and exert a lot of force in his jump to allow enough momentum for him to perform a back flip. Also since he is doing a back flip with no movement of any kind forward, he should be landing around the same place not in the location he is landing right now. The overall back flip has to also be quicker, particularly at the ending sequence of his back flip. You did however show better easing and flow, you just need to focus on some movements. I recommend looking at some videos that demonstrate certain movements. You can even do simpler actions your self like running or a proper punch.