Steinberg have released a free spectral synthesizer X-Stream which can be used to stretch and playback samples and “create ethereal dreamy textures and soundscapes”. It works with teh free Halion 7 which loads as a vst3 instrument. To download it you will have to create an account on Steinberg.net.
X-Stream includes a number of effects and modulators on board.
If you want to create soundscapes and big sweeping pads, then I suggest that you have a look at this instrument. There are a number of videos on YouTube that illustrate the use of X-Stream.