Why Lim Chang-yong was absolutely broken

In every single season of the KBO from '97, '98, '99, to '00, when the league was gradually shifting toward a pitcher-dominated era
(and the '99 season was an all-time legendary hitter-vs-pitcher battle season)
he maintained a WHIP in the 0.9 range while throwing around 130 innings as a middle reliever (though he only threw 90 innings(?) in the '00 season;)
Even with skill and stuff past his prime, he succeeded in the Japanese league and made it to the MLB, so during his peak, compared to the KBO level... well;;
There is a lot of talk regarding his personality, but as a player, I feel he might have even been on the level of Kim Byung-hyun, which makes him a somewhat regrettable figure in my personal opinion.