Javelin and Holy Trail Dmg issue

Tooltip is showing 75,000 dps for 'Holy Trail" while 4 sigil’d in my current gear @ lvl 85

My question: How much damage reduction do mobs have baseline and how does level disparity affect our damage?

If I enter empowered echoes @ 85 do I get a penalty for level difference? My javelin’s “Holy Trail” is ticking for 1/12 of the damage of the tooltip.

~90% at lvl 100.

XP is capped to your lvl + 5 so if you’re lvl 85 then you’re getting xp as if you were in a lvl 90 zone.