a.cs

class Transformable<T>
    where T : Transformable<T>
{
}

class TransformationContinuation<T>
    where T : Transformable<T>
{
    T origin;

    public TransformationContinuation(T origin)
    {
        this.origin = origin;
    }

    public T Then()
    {
        ... // Delays?

        return origin;
    }

    public TransformationContinuation<T> Then(Action action)
    {
        ... // Do something with action

        return new TransformationContinuation<T>(origin);
    }

    public static implicit operator T(TransformationContinuation<T> continuation) => T; 
}

class Drawable : Transformable<Drawable>
{
    public TransformationContinuation<Drawable> ScaleTo()
    {
        ...

        return new TransformationContinuation<Drawable>(this);
    }

    public TransformationContinuation<Drawable> RotateTo()
    {
        ...

        return new TransformationContinuation<Drawable>(this);
    }
}

class Sprite : Drawable { }

usage:
1:
    Drawable d;
    d.ScaleTo().Then().RotateTo();

2:
    Drawable d;
    d.ScaleTo().Then().RotateTo().ScaleTo().Then().ScaleTo();

3:
    Drawable d;
    Sprite s;
    d.ScaleTo().Then(_ => s.Alpha = 5).ScaleTo().Then().ScaleTo();