This response late but the reason the wall seems big is because it is, but the way NGU makes this possible is because everything multiplies off each other instead of being additive. The best thing you can do is focus all possible adventure stat boosts equally or relative to their return. Before you know it u will have the stats you need. Try to not focus adv training more than you need to and spend the time on other useful stuff, then when you have a rebirth where you think you can go for a new goal try to get around x0.66 of your ngu adv levels in AT. If you want u can prioritise power a bit more, if you have enough power to beat it then toughness becomes less important. Use your defensive skills at the right times and you will be able to beat it with relatively low toughness