This may not be a big of a deal.. but for some odd reason if you spawn or spawn some NPC's in they can become immortal to all damage after being hit by the fire in this mod.
I checked console and from what I can tell either the NPC's I was using either glitch and becoming immortal. Or aren't programmed to be damaged by spreading fire. (I was using Black Mesa NPC's and in the game the fires were made to spread but mainly stayed where they were) for anyone who maybe wants to solve this and clarify with me
Here is the line of code in console while these NPC's were immortal.

[ERROR] lua/weapons/weapon_throwable_axe.lua:488: Tried to use a NULL entity!
1. GetClass - [C]:-1
2. v - lua/weapons/weapon_throwable_axe.lua:488
3. Call - lua/includes/modules/hook.lua:84
4. DeathNotice_PlayerPoints - lua/entities/npc_vj_human_base/init.lua:4223
5. PriorToKilled - lua/entities/npc_vj_human_base/init.lua:4096
6. unknown - lua/entities/npc_vj_human_base/init.lua:3809
7. TakeDamageInfo - [C]:-1
8. BurnThink - lua/entities/vfire/shared.lua:826
9. unknown - lua/entities/vfire/shared.lua:620

File exists in two addons - possible conflicts! lua/entities/npc_vj_human_base/init.lua (VJ Base and Throwable Axe)

[ERROR] lua/weapons/weapon_throwable_axe.lua:488: Tried to use a NULL entity!
1. GetClass - [C]:-1
2. v - lua/weapons/weapon_throwable_axe.lua:488
3. Call - lua/includes/modules/hook.lua:84
4. DeathNotice_PlayerPoints - lua/entities/npc_vj_human_base/init.lua:4223
5. PriorToKilled - lua/entities/npc_vj_human_base/init.lua:4096
6. unknown - lua/entities/npc_vj_human_base/init.lua:3809
7. TakeDamageInfo - [C]:-1
8. BurnThink - lua/entities/vfire/shared.lua:826
9. unknown - lua/entities/vfire/shared.lua:620

Attempting to create unknown particle system 'blood_trail_red_02'
Attempting to create unknown particle system 'blood_trail_red_01'
Attempting to create unknown particle system 'blood_trail_red_01'
Attempting to create unknown particle system 'blood_trail_red_01'
Attempting to create unknown particle system 'blood_trail_red_01'
Attempting to create unknown particle system 'blood_trail_red_01'
Attempting to create unknown particle system 'blood_trail_red_01'
Crazy angular velocity on entity [420][vfire_ball]
Origin: [-300.188324, 4654.407227, 105.113571]
Angles: [-10.886069, 48.416878, 354.967133]
Velocity: [1132.734497, -643.186096, -169.829407]
Angular Velocity: [4671.493164, -349565.656250, 1343459.375000]
Defusing!
Removing!
Giving Z01nk a pist_weagon