akr71
Hero
But as an I intelligence, not a good, will it chose to use that ability? The likely result of geas on one PC to drive it to go do something the others do not want is... they break this control and toss this weapon into a very very very deep dung heap.
Few parties will allow one of their own to be compelled into service by "strangers" against their will and if someone starts acting strange etc the suddenly wants new course, there will be exams etc.
The geas club like any tool needs to be used well or it actually goes against your purpose. At the level of a group getting their hands on an artifact they likely have access to Revivify and Remove Curse so heavy handed and such is less likely to succeed than biding one's time for getting a willing ally.
I have considered these questions. Neither the item's owner, nor the item (nor the DM for that matter) wants to send the characters to their death. The goal is to defeat a particular foe and if they aren't ready to face it, both the item's owner and the item will know it. The last thing the NPC bestowing the artifact upon them wants is for the artifact to end up in the hands of its ancient foe.
I've got my work cut out for me to first do a bit of a lore dump about the item, and how to implement the geas-like features over time. It will ramp up as the party gets strong enough to handle the the baddie.