Since you're nearing Endgame Content... I'd suggest to start farming dungeons that give Tomes of Philosophy and/or Mythology.

Castrum Meridium and The Praetorium only give Philosophy Tomes so start there before you attempt Ampador Keep or Wanderer's Palace since two dungeons are speed runned.

Darklight Gear that can be purchased at Revenant's Toll usually have item level 70 and it becomes necessary to have that gear to attempt even Titan hard mode.