I honestly recommend you spend a session (at least a coupla hours) on the cords section. You'll realise what a sound investment it was afterwards. Anway you can get what you want here without going into cords
OK, you've got a loop but want a bit of -release- i think on it. So...
Hit Edit Preset. and find your way to Amp Envelope in the Edit Voice menu - sleect Rls1 rate and try a setting of around 70 to begin with - play your loop and you should here what you're after - tweak until it's how you like.
If this fails go into sample edit, tools 1, loop tp, and make sure Loop in release is set to on.