From the 'Disappointed...' thread, i got the idea for a puzzle concerning mid-fight-lvlups.
For discussion i think it's better to make a new topic. So here we go:
For the ding spike one could do a puzzle. Following idea:
Have a boss with berzerk and some minions.
One would need to kill the minions to lvlup (-> 2), so one can survive on hit from the boss.
Problem: The boss does too much damage to hit him a second time.
If one hits the boss the first time, he shouts 'Defend me, my minions'.
-> Kill some minions for lvlup (-> 3) *Remark
Hit boss. From berzerk does too much damage for a final strike (Boss shouts: 'Damn minions, i think i should fight myself.' -> This is a fluff-text that berzerk gets activated.)
Kill rest of minons for another lvlup (-> 4)
Remark: After lvlup to 3, one could kill the rest of the minions for the lvlup to 4. This would be a trap, since lvl4 health is not sufficient to kill the boss.
I don't know if it's too obvious... If so, one could try to hide the solution somewhat. But i would think that this puzzle teaches mid-fighting-lvlup and has also a nice story.