Yeah, my question is pretty much the same... Why Helm specifically? I mean, presumably the player has selected one of the domains that the book says Helm has-- Life or Light. I would imagine the issue is probably that there are no Chaotic Neutral gods that have Life or Light as their domain.
If the PC is a Light domain cleric, their options according to the Basic Rules are:
Helm (LN) protection; Lathander (LG) birth and renewal; Milil (NG) poetry and song; Sune (CG) love and beauty.
And if they are a Life domain cleric, then their options are:
Chauntea (NG) agriculture; Eldath (NG) peace; Helm (LN) protection; Ilmater (LG) endurance; Lathander (LG) birth and renewal; Lliira (CG) joy; Selune (CG) moon; Sune (CG) love and beauty.
So in both cases... there are no CN options, and the only ones whose portfolio could be tied to a more combat-centric base are Helm and Lathander-- a LN and LG deity respectively. The only Chaotic deities with Life or Light as their domain have portfolios of Joy, Love, and the Moon. So its not like your player has much of an option about changing away to a Chaotic deity if they see themselves with a more militaristic bent.
Alignment-wise... the closest your player could probably get to the portfolio of a Helm-like deity is Tempus, the True Neutral god of war. But Tempus of course does not have the Life or Light domains though, so you'd have to give Tempus the PC's domain if you wanted your player to switch to a deity who portfolio was closer to Helm, but whose alignment was closer to how they played their character.
But then again... even that might not work for you or the player. They just might like Helm and not want to switch to Tempus, even if the alignment is closer and the portfolio is okay. In that case... you pretty much have to just find one facet of Helm's portfolio that the PC could focus on that had a potentially more Chaotic bent.
A potential idea in that regard would be that the PC is a believer in the Heresy of the Threefold God and/or belongs to the Eye of Justice. Although the Heresy believes that Helm, Tyr and Torm are the same god (who were LN, LG, LG) respectively... they were originally recruited out of the Night Masks criminal organization. There is definitely a vigilante streak that runs through the Eye of Justice organization, and thus the idea that one of them is Chaotic is not out of the question; if you are a vigilante, you are fighting crime counter to the laws and law enforcement system already in place. So that's one possible idea to explain away a CN cleric of "Helm".
If the PC is a Light domain cleric, their options according to the Basic Rules are:
Helm (LN) protection; Lathander (LG) birth and renewal; Milil (NG) poetry and song; Sune (CG) love and beauty.
And if they are a Life domain cleric, then their options are:
Chauntea (NG) agriculture; Eldath (NG) peace; Helm (LN) protection; Ilmater (LG) endurance; Lathander (LG) birth and renewal; Lliira (CG) joy; Selune (CG) moon; Sune (CG) love and beauty.
So in both cases... there are no CN options, and the only ones whose portfolio could be tied to a more combat-centric base are Helm and Lathander-- a LN and LG deity respectively. The only Chaotic deities with Life or Light as their domain have portfolios of Joy, Love, and the Moon. So its not like your player has much of an option about changing away to a Chaotic deity if they see themselves with a more militaristic bent.
Alignment-wise... the closest your player could probably get to the portfolio of a Helm-like deity is Tempus, the True Neutral god of war. But Tempus of course does not have the Life or Light domains though, so you'd have to give Tempus the PC's domain if you wanted your player to switch to a deity who portfolio was closer to Helm, but whose alignment was closer to how they played their character.
But then again... even that might not work for you or the player. They just might like Helm and not want to switch to Tempus, even if the alignment is closer and the portfolio is okay. In that case... you pretty much have to just find one facet of Helm's portfolio that the PC could focus on that had a potentially more Chaotic bent.
A potential idea in that regard would be that the PC is a believer in the Heresy of the Threefold God and/or belongs to the Eye of Justice. Although the Heresy believes that Helm, Tyr and Torm are the same god (who were LN, LG, LG) respectively... they were originally recruited out of the Night Masks criminal organization. There is definitely a vigilante streak that runs through the Eye of Justice organization, and thus the idea that one of them is Chaotic is not out of the question; if you are a vigilante, you are fighting crime counter to the laws and law enforcement system already in place. So that's one possible idea to explain away a CN cleric of "Helm".