Thank you for responding so quickly.

That does help.

Usually here we reflect strength in terms of how powerful they are against the average person. So say Hayate is as strong as the next person he is a x1 character for strength. In his Avatar form is he 3 times as strong as normal Hayate (eh normal person) or 4 or 5?

I understand entirely what you mean. The reason I am asking this is because each ability (strength, speed endurance, durability) will be another effect that goes into the calculations for how strong your character can be.

At the moment you have a few numbers to play with, so what I suggest is pick a few abilities - probably strength and durability make sense here, and anything else you think is appropriate as it is your character - and we can assign a number to them. A multiple of 2 or 3 sounds about right for this 'iron giant'.

Then in later levels you can make him stronger.