You mean the supersaws at 2:20? There are countless tutorials on it and there's at least one in each house/edm oriented presetbank. Just go to YouTube and search for supersaw, hypersaw, polysaw, or just saw-synth.
But to get it that aggressive yet nice and clean:
- Don't rely too much on a heavy unison detune, or you'll end up with an amateurish harsh swirl in your sound.
Go with a moderate and smooth detune, and let the aggression come from other things.
If you however feel you still need to go with a heavy detune, then I'd recommend you to use a lot of unison voices (we're talking about 12-16 voices rather than the standard 6-8). Though I'm not sure how good that many voices would translate to a monophonic lead.
- Add a light and very fast pitch-LFO, as fast as you can get it. Just a little, and it will make the sound more rough. If you end up with a cheap swirly sound instead, that could mean that you can't have a fast enough LFO-speed.
For the Massive-synth, just use the vibrato, and maximize the rate, then set the level knob to perhaps 8 or 9 o'clock.
- Add a very fast volume LFO or tremolo, maximize the speed, then just blend in the LFO mix a hint (be gentle), this can also make it more rough.
You can also use ring-modulation to mimic a fast tremolo, and then it will be keytracked, meaning the result can get smoother if it got a little out of control using LFO's.
- Try using more white noise than you first think may be needed, the synth in your example is drenched in it.
- Use light distortion in several stages.
Then in the effects chain they seem to have added compression after the reverb, making the reverb swell up after synth notes are released.