All way too complicated. Ultimate AstariArcher:
Assassin 6 / BattleMaster 6
Rogue 1
Rogue 2 - Cunning Actions - practice hiding, shooting, hiding again.
Rogue 3 - Assassin - Always open with this, from stealth. You get auto-crits, and you attack back
Rogue 4 - ASI Dexterity - Better initiative, better AC, better Attack, Better Damage, better Skill Checks
Fighter 1 - Archery for +2 Attack/DMG on your bow
Fighter 2 - Now you can Action Surge. Do this during your surprise round, especially with Arrows of Many Targets, watch it crit on groups!
Fighter 3 - BattleMaster : Push or Trip attack, Precision Attack, Disarming Attack
Fighter 4 - Sharpshooter - Toggle this on and never toggle it back off. +10 Damage each shot. With everything you took previously, the -5 to attack is already negated.
Fighter 5 - Extra Attack, now things really take off. Be sure to have 'Favorable Beginnings' from your illithid things for another guaranteed crit
Fighter 6 - ASI Dexterity - Better initiative, better AC, better Attack, Better Damage, better Skill Checks
Rogue 5- Uncanny Dodge, 3D6 Sneak Damage
Rogue 6 - Skill Expertise of choice.
No need to respec, however this build assumes you start with 16 Dex instead of 17; so you'd respec as soon as Withers comes to your camp.
You will gain awesome stuff *every level* and will always be on par with the challenge, regardless of difficulty. Will always be good for traps and locks, and with special arrows can take entire groups of foes. Especially the Arrows of Many Targets will absolutely *slaughter* your foes. Combine this with the ring of +2 Acid on weapon damage and the gloves of +1d4 Fire damage and this will be the hardest non-caster striker.
