I got this from Focusrite which solved the problem I was having, which was low latency monitoring using the onboard reverb....really don't know why the tutorials are not as concise as this...
First set up a track in Cubase to record onto.
Then, ensure your MixControl is on the Input FX, not VRM, setting.
Reverb Returns is a fader that represents the amount of reverb signal to be included in the Mix, as defined per channel, by the Reverb Send. Don't worry, you will know what I mean in a moment.
At the very top of MixControl, you will see a tab called Reverb Send. Click it and you will see the faders move around to represent what volumes things are in this area, and thus to represent what audio sources in your Mix will have reverb on them. You will also see controls for the reverb in general, such as room size etc.
The trick is to ensure that reverb is only applied to what you want it to be applied to. Assuming you are using Input 1, ensure the fader called Anlg In 1 is turned up, and everything else is turned down. Also, ensure that Anlg 1's pan fader (at the very top, right underneath where it actually says 'Anlg In 1' there is a horizontal fader with 'L' on one side and 'R' on the other) is in the middle, on 'C'.
Then go back to Mix 1, and turn up the Reverb Returns fader. You should now start to hear reverb on your single input, but not anything else. Make sure that Anlg In 1 in Mix 1 is centrally panned too.
If anything goes wrong, or things look different to what I have described, then go to File > Restore Factory Defaults and then go through the process again.
I have attached screenshots of both Mix 1 and Reverb Send to show you what I mean.
That should cover it. Please let me know if I can be of any further assistance.