Monster Hunter World Iceborne - Fade to Black (Fatalis) Insect Glaive 21'43"56／ミラボレアス 操虫棍 ソロ
A test run using 4 fatalis β armor set+brachy chest β, Tool Specialist 5 is very neat in this fight, a rec skill to use temporal mantle against fatalis.
Investigation quest I used kaiser head β -kulve chest β-alateron arm α-kaiser waist β-kulve legs β and safi glaive with teo essence. Guts from 2 kulve set skill helped sometimes and speed eating is nice to use mega potion quickly.
Heavy Artillery is nice bonus dmg when using railgun (aiming its chest and head) you can put this skill in mantles.
Not sure if Defense Boost and Fire Resistance are useful here so you can put others there.