Going by this page https://namu.wiki/w/V 매트릭스 skill description of the various nodes in KMS, they also do not have the reduced MP consumption effects in their skill description (search in text 쓸만한 어드밴스드 블레스). So it is most likely intended for the 5th job skill "Decent Advanced Bless" to not have the MP consumption effect.
(According to their revision history of their wiki page https://namu.wiki/history/V 매트릭스?from=127, before revision 126 (October 4, 2017), their wiki page said advanced bless has the MP cost reduction , after revision 126, they removed the MP cost reduction text)
This bug is caused by your computer being on for more than 24 days (can be check by going to task manager > performance tab > up time), and will not be fix until you reset it back to 0 by doing one of the following.
(A feature of window 8/10 called hybrid boot prevents the up time from resetting back to 0 by normal restart and normal shutdown by loading a backup copy of the RAM including the up time number)
Disable Hybrid Boot permanently: In order for normal restart and normal shutdown to reset the up time, control panel > power option > choose what the power button do > turn off hybrid boot (fast start up), then restart your computer.
They are fire immune (one of the few monster to have 100% fire resistance), use the beginner skill "elemental slash" to deal with them since it is your only skill that is not a fire element, or use the 4th job skill "Fire of Recreation" to add a secondary effect "decrease monster elemental resistance by 0.9x" to your 2nd job skill "Ignition" so all your fire based attack can deal 10% of their original damage.
