Guests
The majority of the 30 Tier-1 Summons had a higher star rating.
Higher star ratings indicated better potential, which made it much easier to break through the barrier separating the Tiers.
That was also why the Nature Spirit and all 3-Star Subjects advanced to Tier-1 even though they had been summoned only recently.
Other than that, many Combat Summons had advanced to Tier-1 thanks to the support granted by external means, and the energy influx they obtained from killing Monsters.
Michael didn't venture out to hunt often, but his War Rune had also reached the low refinement degree of the 1st Tier by now. The soul share he received from his subjects was quite high, after all.
Even though his territory had grown much stronger than before, it opened a lot of opportunities for them to explore. In fact, it was because of the strength they gained that they had a lot more things to do.