Need help

[Sir cryosin]

So I created a charter for my brother to join are game. I was talking about a bladelock and was cool that sound fun to play. We rolled it up fighter lv1 the 2lvs of warlock fiend contact. He's going to hit warlock lv3 next game and I don't know if he wants to stay on the path of blade local or something else he love the eldritch blast and his next invocation he might pick up eldritch spear to double it's range so. My question is how do help him come up with his charter development I'm just don't want to gimp his character because. I had a ideal for a charter concept that sounded cool to him but now he's playing and liking something else.

[CantigThimble]

He can definitely go pact of the Tome instead of blade and still make good use of his fighter level. Pick up Shillelagh and Green-Flame Blade so he's still a very competent melee fighter if he ever gets caught in a situation where that's necessary and the rest of the time he's just a warlock with a much better AC than normal. A level in fighter will barely gimp his progression in blastlock at all since EB is based on character level not warlock level. If you're really concerned about him having a suboptimal build then you could let him swap out his fighting style for armored since he can use that effectively without ever making melee attacks.