Dragon slayer is a defining point during making a character in real rsc and in rscr, in real rsc depending on your goal you would chose to do the quest at a particular level, such as 1 def for a drag axe pure giving you about 8 def, .. in the past on rscr you would need to do it with nearly no def in order to land on 40 def, then with subs and other things that added higher exp rates people would do the quest for higher def and str xp vs hp, there has also been A few bugs that allowed for lower than the rscr norm defence drag axe pures..
I sujest if a player finishes the quest they should then go to the champions guild master to claim their exp, being one of 3 choices, exp per lvl + very low base exp, flat 20k, or the old rate effected by exp modifiers.
In the end it will even the playing field forplayers who hadnt taken i had the chance to take advantage of bugs or conditions of the past.