without rat help，i managed to make it lol
sewer，ask willow to practice in arena，the fairy。
looks like the game don't know how many units in my team.
in sewer sometimes i can get two rats but no more, with MC /Asara/Galu? five unit max. can't summon skeleton or use rat talisman. everything back to normal after start a battle(but if i don't get 8 unit in team, or kick out some,i can't use talisman to get them again)
in arena, i challenge the rock gaint. The second and third left empty. Just like Asara and Galu here but not exist. The rat start from the fourth and end at the second row. Five rats for me.
fairy, the talisman can be used, but no rats appear in team. skeleton and demon are OK.