Quote “for example if you have 1000v 1 amp is 1000 watts output.. if the coil has 100 ohms for example it will consume 100 watts to conduct such current to the load.. but lets say the reaction this current causes is different on the input transformer.. we must measure it.. and come to a conclusion ...”

I think that you will have to learn a bit more about coils, a 1,000v across a coil would depend on a number of things first, DC resistance that you said was 100ohms, then you will need its reactance XL, is it DC power r AC power I assumed that you meant that it was DC 1,000V and the coil had a DC resistance of 100ohms.

Now you will need the inductance of the coil. Then you can put the inductance over the resistance to give you the time content T , then you can construct a curve to the 5T.

Once fully at the 5T period the coil will then pass full current, 1,000/100 = 10amps this then results in 1,000 x 100 = 10,000watts.