Magnus didn't expect that he would be defeated using the same trick…
He had strengthened and improved his control over his Demonic Eyes just to ensure that he wouldn't be defeated by this lowly mana-draining technique.
However, because he was controlling his Flame Dragon Lightning, he had difficulty activating the powers of his implanted eyes.
It doesn't mean that he can no longer activate these eyes but it would require more effort and he only planned to do it if he noticed that Vincent started casting another Mana Art.
In the end, he failed to notice the Mana Drain's activation until it was too late.
The drain in his mana was too subtle that he didn't notice immediately.
"Tsk… Just what kind of technique is that… I'm not even near you…" Magnus grumbled as he recalled that Vincent's Mana Drain before has short cast range. Even if it had gotten larger, the draining rate shouldn't be that fast if the distance was wide…