From: Gatarix | #048
He's fighting invisible enemies, though -- if Seymour is going to camp the base, then he can't dispel.
In any case, I'm kind of skeptical about Seymour dispelling the invisibility in the first place. If Seymour were fighting Zeratul or someone, would he waste time standing there casting dispel instead of attacking? Offhand, I don't recall Seymour having any experience with magical invisibility such that he'd necessarily think "this is a buff, I should cast dispel."
Well if the enemy team isn't camping somewhere they can't really use invisibility to its optimal use with the short duration as they won't know for sure they're coming on the enemy. So if they come to Seymour and he's camping he's going to know to dispel the entrance (or blast it-- either works really).
Also I think this is one of the few matches where MP may come into play. Jake may simply run out of mental energy casting buffs repeatedly and healing Duke repeatedly early in the match (cause as I said he has no knowledge his healing won't work so he may use a good few fruitless castings). As I understand it he's not really a hardcore caster so yeah.
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