What VST did Nifflas use for his earlier pads?

Can't believe this subforum hasn't had posts since 2015. Here's hoping someone's looking!

I'm wondering if I could know what VST was used during the Knytt/Knytt Stories days for a lot of pads Nifflas did. Nifflas' sample pack has a lot of pads that are from the same software it sounds like. I've always assumed it's the Crystal VST, but it would be nice to get confirmation. It's certainly something like Crystal that has some FM synthesis going on, am I correct?

Nifflas used EnergyXT and it comes with its own synthesizer. I know for a fact that he used that a lot.

In fact, I bought EnergyXT for that reason.

In addition he uses Camel audio Alchemy, but I think he didn't use that yet when he worked on Knytt Stories.

Nowadays he uses the true power of Unity 3D and programmed his own audio engine.