>>536996398
you can only technically have one forcefield at a time, its why Flutterpage Insight text is an entire essay. It specifically overwrites the previous one

Kassandra has special text that says "I cant stack forcefields" incase reading is hard. Instead she gets a separate self buff.

In the case of the skill tree you get the forcefield you picked first which is why you need to complete 1 skill tree before moving on

>>536996545
The level 1 is the forcefield, level 3 just buffs the forcefield further. It doesnt really matter though cause you have to get level 3 anyway