Anyone find it yet?

I had this weapon drop from an enemy in the southernmost part of the map, near the fort where the blind girls father is. One of the enemies along the wall surrounding the area had it.

I have been grinding for this for more than an hour.

Best farm for these is from Windmill Village grace go down the stairs immediate right straight towards the farm where two of them spawn you can kill one while other has Visions of Mushroom

I got lucky and this dropped for me while I was just going through the Morne Castle quest. It's been my primary for a while but I'll have to give the other greataxes a try once I decide to pump my str up past 24.

Compared to the Greataxe (the weapon by the same name, not the type) weapon you get from the convoy near Waypoint ruins, Longshaft Axe has about 5% less base damage but ~15% more STR scaling. The two weapons have an identical moveset with the Longshaft Axe being about ~40% longer than the Greataxe. Afaik Longshaft Axe is the longest greataxe in the game. While fine on foot, it shines as an excellent mounted weapon.

Regarding farming for it, if you're a low level or struggling with the axe-wielding misbegotten's delayed attacks, try spamming jump r2s while standing still in front of them. Even with a slow weapon, it's faster than any of the misbegotten's attacks and each hit with a heavy enough weapon (e.g., Any Greataxe) will keep them stagger locked. My fresh out of the gate level 7 Hero was able to do this after making a b-line for Greataxe and then heading to the Rampant Gaol site of grace to farm.

The weapon art it comes with is War Cry

mario needs to save princess peach again

This should have been 100 miles long