Understanding Maplestory and how amazing it actually is from a average gamers view.

Masteria was created by Nexon America and not Nexon Korea, right? Nexon America seems to have trouble with monster invincibility frames. BF, wolf spiders and elderwraiths all that invincibility frames problem.

There isn't a single publisher that delt with invincibility frames for the mobs instead of characters except NA. In that sense i guess you can sympathize with any screw ups they make, especially if korea was involved and things were lost in translation.