Something I have noticed when people talk about blade lock MC.

[Spacehamster]

People always say to go 1 level fighter for heavy armor, but why not
go 1 level war cleric or another cleric that gets heavy armor as a level 1 feature?
That way you also get level 1 spell slots that you can use for hex so you can conserve
your limited warlock spell slots for higher level spells. Sure need 13 WIS which is a
drawback but WIS is a good save stat anyways so its not the biggest loss.

[dejarnjc]

People always say to go 1 level fighter for heavy armor, but why not
go 1 level war cleric or another cleric that gets heavy armor as a level 1 feature?
That way you also get level 1 spell slots that you can use for hex so you can conserve
your limited warlock spell slots for higher level spells. Sure need 13 WIS which is a
drawback but WIS is a good save stat anyways so its not the biggest loss.

Mostly for the fighting style. Also for second wind.

[Byke]

Mostly for the fighting style. Also for second wind.

+ con saves

[Varlon]

Fighter also gives CON save proficiency, which will help keep Hex active. (also +2 HP compared to Cleric)

[Aett_Thorn]

Also less MAD, since you don't need to have a 13 Wis for the MC. You need Str/Dex, Con, and Cha already. Adding Wis to the mix just makes things more painful.

[Foxhound438]

the big thing for me is requring wisdom.

Vuman fighter/lock starting stats: 16/8/14/8/10/16, PAM or GWM out the gate
Vuman cleric/lock starting stats: 16/9/14/8/13/14, PAM or GWM out the gate

As you can see, you lose out on +3 starting CHA. You can go normie human, but it'd cost you your feat:

Normie cleric/lock starting stats: 16/9/14/9/13/16

It's up to you if getting that extra slot, spell options, and domain feature are worth it to you, but you do lose a feat and a fighting style to get it. I personally wouldn't.

[DarkKnightJin]

Since Hexblade is pretty much designed to bump Bladelock's potential, starting with a level in Fighter gives you everything you want in a melee character. Option for heavy armor, shield, a fighting style.
Probably Defense or Dueling since GWF isn't that great for a class that can use their casting stat in place of Str or Dex if they use a 1 handed weapon.

Not to mention starting proficiency in Con saves, which will help in keeping Concentration up,ost likely on things like Hex, or debuffs on the enemy.
Something like Hold Person comes to mind. Bump Cha for a good DC to beat, and a nice bonus to your attack rolls. Then wail with Advantage against the stunned BBEG and get autocrits.
Maybe even dip some Rogue or Paladin to bump it up with more dice to double on those crits.

Not to mention any Rogue, Pally, and Barb in your party will LOVE you if you can lock a guy down like that, and they can just take 'em to church.