RinoZ
It could that there is an ant monster or a colony of ant's on a much lower level of the dungeon that terrifies the cult enough to not want Anthony to live long enough to become that monster. It is the only reason i could think of for them picking on him so much. Well actually I guess maybe because the worm is such a weak creature at its start it(the worm that the cult worships) left behind certain knowledge. For instance, the weaker you start at the more terrifying you can be at later levels because you have so many way's to grow. Ant's and worms are probably two of the weakest creatures at level 1 so Anthony would definitely fall under that category. I guess also there could be some kind of prophecy that states an Ant destroy's or severely harms the cult. This is unrelated but I really want Anthony to talk to Grannin about the itch and his interactions with the Dungeon creator or consciousness itself. As a reader I really want to know if either of those things is rare for a monster with a human consciousness and what those two things might mean for Anthony in terms of his strength,potential, or talent. I also really want him to let Grannin see his core because I am interested to see how Grannin would react with all the knowledge that he has at his disposal. I imagine that will happen once Anthony is desperate enough, as a result of one of his opponents being unbeatable by any combat technique or strategy that he (Anthony) can come up with.
I dont know how big the colosseum is, but i know unless this speedster runs along the walls it will not eScape. It will need a stronger outwards force to counter the inwards force i.e. centripical force is to planets, Gravity is to the Sun. the vacuum is the suN, opponent is the planet trying to Escape the pull.