The lead synth sounds too thin so a way to help your synth lead fit into your mix is to mess with the automation envelopes and also add a touch of reverb, compression, and delay. Experimenting more with the effect chain, for example if you add a compresser before the reverb and delay, you'll notice that it sticks, it sounds glued together. but it isn't always like this depending on how the synthesizer is functioned. Hope this helps.