Especially ferocious with とりわけ
Vocabulary Explanation: Especially with とりわけ

Following a potential lead on trainers’ Pokémon having gone missing, Red sneaks aboard a ship docked at the harbor. There, he’s confronted by Machisu. As the single Pokémon with Red was already hurt in a surprise attack, Machisu offers to finish it off with his prize Pokémon.
- マチス:
- 「こいつはとりわけ凶暴でな。ボールに入
( れることもままならん。」- “This one is especially ferocious. It can't even be put into a Poké Ball.”
Key Points
とりわけ means especially
Machisu singles this Pokémon out as especially ferocious.
It raises this one above the general level of danger.
こいつ is rough
こいつ means “this one” with a blunt tone.
The second sentence proves the degree
ボールに入
( れることもままならん means even putting it in a Poké Ball is not manageable.The も supports the idea that it is exceptionally hard to control.