NotSoLoneWolf

I think a good place to start would be the Andromedon Shell's X2Ability file, as it lays acid across the ground where it walks in a similar fashion to what you are describing here.

Can you provide the rest of your code? I'm trying to replicate this for my own regeneration effect and I'm stuck on the: static function X2Effect_Persistent CreateShieldRegenerationEffect(X2Effect_EnergyShield ShieldEffect, string FriendlyName, string LongDescription) Specifically, the first parameter "X2Effect_EnergyShield ShieldEffect". When I call the function, I obviously put the name and description as parameters 2 and 3, but how do I write parameter 1?

LevelUpBarracks console command will give everyone in your Barracks one level of XP. Other than that, there is no way to do it to an individual soldier using console commands or using mods or by editing the save files. There may be an external cheat engine or something, but I haven't found any. The workaround I used back in XCOM: Long War was to manually add or remove abilities in-mission so I could respec soldiers I messed up, but I don't know what the codes are for that in XCOM 2.