I've seen 25s frequent with my Iban, actually more frequent than godmage. I agree it may be a bit overpowered. I say raise it no more than 50 casts per recharge and recharge no closer than ardy. I wouldn't object to max hit being lowered to 20. I got 4 kills in 14 casts with my most recent charge, therefore any more than 50 casts and you may as well make it unlimited. I 3 hit a level 99 on my level 76 with 40 attack and 40 strength using the Iban spell. If players are too lazy to walk across the map to have an extremely overpowered weapon, they shouldn't bother using it.
You can get as many klanks as you'd like for 5k each after completing the quest. You can also pick them back up if you die in the wildy with them. If you can't afford to pay 5k for a pair of gaunts to allow you 1 higher damage, why do you even pk?
You need 25 ranged to drop the bridge the do the quest. Doing it with 1 agility will make you want to commit unalived, however I did it with 16 agility with no problems. It takes like 5 minutes to get 16 agility so if those requirements are too tedious for you, why are you even questing?
In conclusion, the quest is on point and definitely worth the requirements for the rewards offered. The only thing debatable is how OP the staff is, and how fucking hard it is to recharge. If it stays as powerful as it is, it should be that hard to recharge. If it's weakened at all, the recharging system should be made easier.
Nice work guys! Time and effort much appreciated!