Since there are plenty of ways to Special Summon on the opponent's turn, you can utilize both these effects before the opponent's Main Phase even begins, leaving them with only two cards to play with
Actually, let me rephrase that: this Archetype basically takes "Trick-or-Treat" to a rather logical extreme, being able to set up a lot of "Tricks" for your side, while offering "treats" (drawing power) to your opponent in the hope of giving them a proverbial "tummy-ache", if you will
If you do, banish it when it leaves the field
At first glance, it might seem incompatible with Tenyi monsters or Level 7 Brave monsters that state "can only be special summoned when there are no monsters on the field," but the former does not count Normal Monsters as monsters, and the latter can be special summoned by chaining to the effect of Magicians' Souls, so there is really no problem at all in dealing with Bystials
You can only use each effect of "Fiendsmith's Desirae" once per turn