Nerd that Otis is, would he know anything extra about the whole overcharged leyline deal?
If he looked deeply into it, he would know that overcharging a leyline is a risky process that temporarily shifts a small space into that of the Overlapping World of Ascendia - a world that exists simultaneously with the regular one underneath it that's known for its lack of essence and other odd sights. It requires what's known as a 'Fragmented Word of Astra' to perform nowadays, with the associated word being the more commonly known 'Falkris'.
The advantage to overcharging is typically that the one who overcharges and invokes the word will gain that leyline's essence at their temporary disposal in a single massive burst, up to whatever their regular endurance can allow them to channel. Other benefits do exist, but they're said to delve into specifics based on the invoker's prime essence, and thus can't be fully anticipated.
As for downsides, it severely damages or even destroys the leyline, depending on how much the invoker is capable of using in one burst of energy.