Does spike shooter apply the arrow stacking physical defense debuff on enemies?
No. Spikeshooter is melee - physical - Pierce type skill.
however I saw this certain vid that the 2h bow bonus to flying mobs apply to it? or I just saw wrong?
The attribute works as long as you’re equipping a 2-handed bow. It is not missile specific.
but it doesn’t contribute to the arrow stacking physical debuff ?
No.
Because it is a [melee] skill: https://tos.neet.tv/skills?cls=Char3_5&f=1
Only [missile] skill will put arrow debuff, such as: https://tos.neet.tv/skills?cls=Char3_1&f=1
Look at some skills, is [missile attack] - arrow.
So
A. 2 handed bow + melee skill = double damage to flying, NO arrow debuff.
B. 2 handed bow + missile skill = double damage to flying, YES arrow debuff.
oh okay okay thank. are you sure about this though? is this from experience or have u seen it somewhere?
Mine is from experience. Personally have a Sapper 3.