How to make a system that will let elements interact with other elements?

Questions & Answers
1

I already have the hand states setup now but I need to get them working with other things in the scene. Like ice is melted when the fire hand comes near it, when ice is near water it freezes etc.

2

One way is something like this:

void Update()
{
    if ((firehand.transform.position - ice.transform.position).sqrMagnitude < 0.1f)     
    {
        StartCoroutine(MeltingIce());
    }
}

and you define the MeltingIce IEnumerator someway else in the file.

Or you could use an animation system, so instead do something like this:

void Update()
{
    if ((firehand.transform.position - ice.transform.position).sqrMagnitude < 0.1f) 
    {
        ice.gameObject.GetComponent<Animator>().SetTrigger("melting");
    }
}

Just a couple of ideas