Treasure Breach sigils are easiest to build up when you treat the War Plans system as the centre of the run, not as a side activity. A well-built plan turns ordinary elite kills into a steady chain of altars, goblins, and fresh sigils. That matters when you are also chasing runes, tuning prisms, ancestral gear, or Mythic Uniques. Before you head out, check your build, clear some inventory...