After a devastating Impid raid, a normal man in black appeared but the frame rate was drastically dropping, went into dev mode and saw these errors being spammed consistently

-----------------------------------------------------------------------------------------------------------------------------
System.NullReferenceException: Object reference not set to an instance of an object.
[Ref F4E7F632]
at BigAndSmall.TryExecuteWorker.Postfix (Verse.Pawn __result, RimWorld.IncidentWorker_WandererJoin __instance) [0x00443] in <2575124af11f4c7f83fe822e6eed2b40>:0
at RimWorld.IncidentWorker_WandererJoin.GeneratePawn () [0x001a0] in <78bd3c897ba748f7a6d21cc5498c054e>:0
- POSTFIX RedMattis.BetterPrerequisites: Void BigAndSmall.TryExecuteWorker:Postfix(Pawn __result, IncidentWorker_WandererJoin __instance)
at RimWorld.IncidentWorker_WandererJoin.TryExecuteWorker (RimWorld.IncidentParms parms) [0x00017] in <78bd3c897ba748f7a6d21cc5498c054e>:0
at RimWorld.IncidentWorker.TryExecute (RimWorld.IncidentParms parms) [0x0002b] in <78bd3c897ba748f7a6d21cc5498c054e>:0
at RimWorld.Storyteller.TryFire (RimWorld.FiringIncident fi, System.Boolean queued) [0x00023] in <78bd3c897ba748f7a6d21cc5498c054e>:0
at RimWorld.IncidentQueue.IncidentQueueTick () [0x00048] in <78bd3c897ba748f7a6d21cc5498c054e>:0
at RimWorld.Storyteller.StorytellerTick () [0x00000] in <78bd3c897ba748f7a6d21cc5498c054e>:0
at Verse.TickManager.DoSingleTick () [0x00192] in <78bd3c897ba748f7a6d21cc5498c054e>:0
- POSTFIX Owlchemist.ScatteredFlames: Void ScatteredFlames.Patch_TickManager_DoSingleTick:Postfix()
UnityEngine.StackTraceUtility:ExtractStackTrace ()
Verse.Log:Error (string)
(wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.TickManager.DoSingleTick_Patch1 (Verse.TickManager)
Verse.TickManager:TickManagerUpdate ()
Verse.Game:UpdatePlay ()
Verse.Root_Play:Update ()

System.NullReferenceException: Object reference not set to an instance of an object.
[Ref F4E7F632] Duplicate stacktrace, see ref for original
UnityEngine.StackTraceUtility:ExtractStackTrace ()
Verse.Log:Error (string)
(wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.TickManager.DoSingleTick_Patch1 (Verse.TickManager)
Verse.TickManager:TickManagerUpdate ()
Verse.Game:UpdatePlay ()
Verse.Root_Play:Update ()

Skadi already has trait SpeedOffset
UnityEngine.StackTraceUtility:ExtractStackTrace ()
Verse.Log:Warning (string)
RimWorld.TraitSet:GainTrait (RimWorld.Trait,bool)
BigAndSmall.TryExecuteWorker:Postfix (Verse.Pawn,RimWorld.IncidentWorker_WandererJoin)
(wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:RimWorld.IncidentWorker_WandererJoin.GeneratePawn_Patch1 (RimWorld.IncidentWorker_WandererJoin)
RimWorld.IncidentWorker_WandererJoin:TryExecuteWorker (RimWorld.IncidentParms)
RimWorld.IncidentWorker:TryExecute (RimWorld.IncidentParms)
RimWorld.Storyteller:TryFire (RimWorld.FiringIncident,bool)
RimWorld.IncidentQueue:IncidentQueueTick ()
RimWorld.Storyteller:StorytellerTick ()
(wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.TickManager.DoSingleTick_Patch1 (Verse.TickManager)
Verse.TickManager:TickManagerUpdate ()
Verse.Game:UpdatePlay ()
Verse.Root_Play:Update ()

System.NullReferenceException: Object reference not set to an instance of an object.
[Ref F4E7F632] Duplicate stacktrace, see ref for original
UnityEngine.StackTraceUtility:ExtractStackTrace ()
Verse.Log:Error (string)
(wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.TickManager.DoSingleTick_Patch1 (Verse.TickManager)
Verse.TickManager:TickManagerUpdate ()
Verse.Game:UpdatePlay ()
Verse.Root_Play:Update ()

Angra already has trait Tough
UnityEngine.StackTraceUtility:ExtractStackTrace ()
Verse.Log:Warning (string)
RimWorld.TraitSet:GainTrait (RimWorld.Trait,bool)
BigAndSmall.TryExecuteWorker:Postfix (Verse.Pawn,RimWorld.IncidentWorker_WandererJoin)
(wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:RimWorld.IncidentWorker_WandererJoin.GeneratePawn_Patch1 (RimWorld.IncidentWorker_WandererJoin)
RimWorld.IncidentWorker_WandererJoin:TryExecuteWorker (RimWorld.IncidentParms)
RimWorld.IncidentWorker:TryExecute (RimWorld.IncidentParms)
RimWorld.Storyteller:TryFire (RimWorld.FiringIncident,bool)
RimWorld.IncidentQueue:IncidentQueueTick ()
RimWorld.Storyteller:StorytellerTick ()
(wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.TickManager.DoSingleTick_Patch1 (Verse.TickManager)
Verse.TickManager:TickManagerUpdate ()
Verse.Game:UpdatePlay ()
Verse.Root_Play:Update ()

System.NullReferenceException: Object reference not set to an instance of an object.
[Ref F4E7F632] Duplicate stacktrace, see ref for original
UnityEngine.StackTraceUtility:ExtractStackTrace ()
Verse.Log:Error (string)
(wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.TickManager.DoSingleTick_Patch1 (Verse.TickManager)
Verse.TickManager:TickManagerUpdate ()
Verse.Game:UpdatePlay ()
Verse.Root_Play:Update ()

Skadi already has trait SpeedOffset
UnityEngine.StackTraceUtility:ExtractStackTrace ()
Verse.Log:Warning (string)
RimWorld.TraitSet:GainTrait (RimWorld.Trait,bool)
BigAndSmall.TryExecuteWorker:Postfix (Verse.Pawn,RimWorld.IncidentWorker_WandererJoin)
(wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:RimWorld.IncidentWorker_WandererJoin.GeneratePawn_Patch1 (RimWorld.IncidentWorker_WandererJoin)
RimWorld.IncidentWorker_WandererJoin:TryExecuteWorker (RimWorld.IncidentParms)
RimWorld.IncidentWorker:TryExecute (RimWorld.IncidentParms)
RimWorld.Storyteller:TryFire (RimWorld.FiringIncident,bool)
RimWorld.IncidentQueue:IncidentQueueTick ()
RimWorld.Storyteller:StorytellerTick ()
(wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.TickManager.DoSingleTick_Patch1 (Verse.TickManager)
Verse.TickManager:TickManagerUpdate ()
Verse.Game:UpdatePlay ()
Verse.Root_Play:Update ()