You need to lose the fight with the dragon, but survive. The easiest way to do that is to cast all protections on yourself and then use the elemental spells.
If you're talking about the berserker mode achievement, then read the response I just gave to vampirekid. If you mean if there is a way to do that by yourself, then no, there isn't. I'll be doing a new game+ after I finish the entire series, where you can get as many stat points as you want, but that will be a long time from now.
For the kneed a break achievement, you'll need to have not shown yourself to Cutthroat Dave in chapter 1 at the beginning. This way, he will confuse you with Eiden in chapter 4, and fight him instead. The achievement is gained shortly afterwards.