So I want to argue on both of your points: first, yes i agree that we did abused the fuel foundation while being warned not to time and time again. But like, what choice did we had? The only time I can remember where we didn't HAVE to abuse it is when we first win again tian fang at chapter 2 (I think?). If we wouldn't have used it against Taio we would've died, if we wouldn't have used it again Jack there was a good chance of us dying (though I don't think Jack would've killed us even if we turned out a bum without using the fuel foundation, mc didn't know that). All time except with Goro's brother and against tian fang were a life or death scenario so it was really either abuse it or die.Oh, cool! Then I will for sure!
I think it comes down to two things, right? The fact that Jack did actually outsmart the MC by making them break their own cores through their Fuel Foundation - and the MC has been warned time and time again that the burst of power they get via their Foundation is unstable and unreliable. And the fact that someone had to intervene with the fight - otherwise the MC would have died/lost.
As for your second point: so what? Sure, if you look at it a certain way then Jack won that fight and we had call in an ally like a *****, but like isn't that the whole point of the trials? Part of being an archon isn't just being the strongest but also be able to get allies even in unlikely places, mediate conflicts and so on. The fact we even had an ally crazy enough to go against JACK of all people in the trials for us shows we were an excellent candidate for being an archon rather then Jack who just solves all conflicts by using either his name or fists. Part of fighting is unfortunately not just your power or techniques but also having resources, knowledge and allies.
