Who is the strongest NPC? NOT MONSTERS OR LEGATE LANIUS , im talking about NPCS that you can actually reach without doing the final mission.

Without a pulse gun? BoS Paladins. Or maybe Legion assassins :bonk:

I didn't think the paladins were hard to kill at all. I thought the elite rangers were the toughest.

The Veteran Rangers at camp golf. Start a fight there and you have allot of Brush Guns, Sequoias and AMRs pointed in your direction.

Legion Assassins seem pretty tough for me. I lured a deathclaw to one and he won which wasn't the plan <_<
I haven't encountered any others yet, so they have been the toughest for me so far.

Those dogs you have to fight when getting the teddy. Especially hard when all you have is a machete.

I thought the Merc squad harrasing J-town was actually a pretty rough fight, these guys were loaded for bear heh.

Lupa, And Assassin's.

Maybe Caesars Guard.