UnassignedReferenceException: The variable _explosion of BattleArtilleryEffect has not been assigned.
You probably need to assign the _explosion variable of the BattleArtilleryEffect script in the inspector.
Rambo.Battle.Fx.BattleArtilleryEffect.OnEffectStarted () (at Assets/Scripts/Rambo/Battle/Fx/BattleArtilleryEffect.cs:18)
Rambo.Battle.Fx.BattleTimeEffect+<WaitAndStart>c__Iterator6.MoveNext () (at Assets/Scripts/Rambo/Battle/Fx/BattleTimeEffect.cs:58)