My character in Kingmaker died. I am thinking of a Brutish Rogue. Someone that will sneak attack with a nodinada (?) d10/18-20x2 I think.
I see him at lvl 5...since the party is lvl 5. I am thinking 3 rogue/ 2 fighter. It is a 20 point buy and am thinking of taking a half-elf as my race so I can get favored class bonus for both classes.
I presume you mean the Nodachi. It's a very good weapon choice; sacrificing damage dice for critical threat range is always a good deal for characters who have other ways of dealing damage (good strength and sneak attacks, in your case). With a high strength modifier and presumably a fair bit of flanking for sneak attacks that should work out nicely for you.
One thing you might consider is the "ancestral weapons" alternate racial feature for the half-elf. You lose out on skill focus, but gain weapon proficiency with any weapon you want. It occurs to me that the Nodachi is a martial weapon, so if you're multi-classing fighter this won't be necessary. If you choose to go pure rogue, however, then this would be the preferable way to get your weapon proficiency.
Another thing you might want to consider is the ninja alternate class. One of the key class features it loses out on is evasion, but if you're going to be wearing medium or heavy armor then you're going to lose it anyways. That means ninja could be a very good deal for you.
The biggest problem with fighter/rogue multi-classes is that they don't scale particularly well at higher levels. They work great at the level 5 range you're building for, but it's downhill from there if you aren't very careful with your build. Definitely plan ahead for where you're going after this.
Had a really nasty brute rogue played in a campaign I ran. 18-str Half Orc (pure rogue) who took the Scout archetype - getting free sneak attack damage on a charge is very nice, and half-orc means you are proficient with one of the best two handed weapons (falchion).
Campaign petered out so I don't know how she'd have done at high levels, but up to level 5-ish she was providing some of the best damage in the party.
I run an 18 Str Half Orc that uses a Falchion.
There are 3 key reasons for Half Orc:
1) Falchion proficiency for a nice 2h
2) Bonus to Intimidate
3) Bite Atk
He is a Scout Thug Rogue.
The Build relies on getting Shatter Defenses and Cornugans Smash.
Rogue Talent allows Str to be added to Cha for Intimidate checks (and Half Orc gives +2 to checks)
The basic premise is:
2h so good damage even when not SA and avoids reliance of full attacks
Having a BIte attack to help maximise SA on occassions when a full attack is possible
Helping the team by debuffing
Charge for Power Atk, Free Intimidate and also Sa thanks to Scout ability.
Mob is shaken (-2 To Hit, Saves)
Thug ability makes the Intimidate last 1 round longer so assuming success, you have at least 2 rounds of a Shaken opponent.
Due to charge allowing an SA on first attack, you can forgo one SA dice to make the opponent sickened (-2 To Hit, -2 Damage, -2 saves)
So at the end of round 1 the opponent has:
-4 To Hit
-4 To Saves
-2 To damage
Is vulnerable to SA from you without the need to flank. So, not only have you debuffed the enemy which makes you the wizard's best friend, but you have lined yourself up to do nice damage without relying on others (and increased the chance of the opponent hitting you or friends)
Full Atk: Mob is Intimidated therefore flat footed, and so SA without needing to flank. Do not use Power Atk unless you need to re-intimidate.
Attack with blade for 2d4+6 + XD6
Attack with Bite (-5 To Hit, hence not using Power Atk in order to maximise chance of hits and SA) 1d4+2 + XD6
One downside to the build is the time it takes to get all you need thanks to stupid Rogue BAB and Feat requirements. A kind GM may let you houserule to fudge some requirements, afterall the Rogue is not exaclty overpowered and it can be the GMs way of thanking you for not being a Ninja :). On the upside, due to high Str, Power Atk and a 2h weapon, the early lvls allow you to Hit hard as a basic in your face fighter type and at lvl 4 the Scout ability at least allows you to get some SA in without the need to flank.
The other downside is the loss of Trapfinding which begs the question why be a Rogue? But if you like the class for what it is then why not.