The amount of Qi needed to summon these nine ancient poisonous dragons is extremely high, and at most, only one can be summoned at a time, requiring the use of elixir pills to replenish the Qi value.
Moreover, the summoning process takes a few breaths and is not achieved immediately, which is completely different from summoning the Heavenly Horse Spirit through the Heavenly Horse Stone Tablet.
This is what makes it difficult to use in arena competitions or battles with expert players, as opponents won't give you that much time to summon. You'd have already died countless times by then.
However, in other situations, it is extremely useful, as having nine Level 100 ancient poisonous dragons is an incredibly terrifying force.
Even Ye Rong himself would have to spend a lot of effort to deal with ancient poisonous dragons of this level and rank, and it wouldn't be easy to achieve.
