In this video you see me (TW server 5 years ago) hit the fighter with a kame lower level with way worse gear. I hit once with a regular kame and then a weakend defense kame for almost 500 damage extra then normal (excuse the crazy talking in the background lol)
This is global with wayyyy better gear and higher level...and im criting 7k and hitting 2k+
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First of all, that fighter has a very low e. def. How do I know? The gear that quests give always has a higher p. def and that being said, we can clearly see that this particular fighter was rather poorly geared. That is the reason why you did so much damage.
Now in the second video, your gear isn't all that great tbh and getting 7k dmg with that kind of gear while being level ~50 is pretty decent. That mob probably had a higher e. def than that fighter in the first video. The update fixed everything and now its harder to play the game, yes. However, damage calculation is the same as in the original TW DBO.
It was way too easy to play compared to the original DBO and I'm glad Daneos fixed everything. Stop complaining, gear up and you'll do decent damage. The only class that can deal a buttload of damage in one hit is crane hermit. You could reach even 500k dmg with good gear 
P.S. only now did I notice that this fighter dealt ~3k dmg with crit on you. His gear was so poor that I am guaranteed you'd do decent enough damage at lvl 40 on him.