I start with this because the tactics should dictate the build, not the other way round. The game seems to push you into having Selen (the rogue) leading the party because she has the highest stealth so is the least likely to be surprised by enemies. However, she seems quite squishy and if she was surprised, then all the baddies picked or her and she often died. My deathrate reduced enormously when I respec'd Vraes into a tank. He was virtually always surprised but could soak up everything thrown at him.

The other unusual feature of combat is that only the defending character receives damage: there is no simultaeous combat. This means that a char with only 1 HP left does as much damage as a full strength one. Damaging lots of enemies with AOE therefore doesn't help much if they survive your turn. Killing the greatest threat. is therefore the aim of every attack. The greatest threat is from long range fire from missile troops of magic dealers. They have a nasty habit of going for your squishiest chars. Make Vraes as tough to hurt as possible and stick him out in front and he will soak up melee attacks - and other attacks if you are lucky enough to have all the baddies focus on him. I try to have him a couple of hexes in front of the others.

However, the AI is not stupid and melee enemies starting next to Vraes will ofter hit him then move past him towards the squishies. This takes me to the 3rd tactic - shoot and scoot. Your units and use their action points (APs) in any order but AI long range units shoot and move but never move then shoot (as far as I know). The best way of avoiding being shot or overwhelmed by nearby melee units is to run like hell. Depending on the distances between you and the enemy at the start of your turn, all but Vraes should be able to get at least 1 shot off, and Vraes may also to give a nearby enemy a smack too. Just remember to leave him enough APs to get back to cover the others.

Don't forget to check your char's health and use healing potions if it's down and there's a danger of getting hit again next turn and dying as a result. It can be easy to forget to check the support characters before spending all their APs by which time it's too late unless the cleric can help. Running out of mana at the end of a turn isn't a problem as long as you glug a potion or 2 next turn.

Initially, I rather ignored defensive buffs. however, they are extremely useful. A fully buffed Vraes set up as a tank is almost invulerable.The buffs are turn-limited, but when you are moving as a party out of combat, there are no turns. I always put the buffs on immediately after resing so the whole stack gets buffed at the same time. Some buffs are only char specific but other work on the whole party.

It is always worth exploring the whole map every time you reach a new area. Most of the goodies (of which there are plenty) are tucked away ih obscure corners. There is a scary alarm that goes off when you get close to enemies. In an evil twist, the devs use the same alarm when you are near treasure. However, the group only splits up with the former so it's good news if the group remains. It is sensible to exploere the map evenly rather than leaving blitzkreig-style open flanks. You do not want surprise a flank attack stomping over the squishy members of your team.

Other points which are more personal choice than anything else. All the text dialogue can be skipped (button top right of screen) but for a first run I recommend reading everything. The story is both interesting and complex.

I also frequently run back to rest and to recharge the buffs. I always hoard potions, money etc in games in case of later need but a more sensible player does not need to. However, there is some very good but expensive kit for sale, especially in the late game, so there is some value in hoarding and running back to rest rather than glugging potions to keep going.

Lastly, the disadvantage of Vraes is that he can't check for or disarm traps, or open locked cabinets. To do those things, Selen has to lead the party. Not a problem as long as you remember to put Vraes back in front before you advance towards the fog of war where more enemies may lurk. Forgetting to do this is good for increasing your death tally. Trust me: I know this....

AS I wrote above, I'm not a great believer in 'best buids' as opposed to 'builds to suit your play style'. 1 good thing in this game is that you can reset each char once for free in each game, and rare loot will give the ability to pay for a very few more.

With that caveat, here is what I am doing in my 2nd proper run-through.

Vraes

Very much designed as a tank with highest points into strength and constitution. High skill with polearm (I only use spear and shield as best defensive combo and spear is fine for polish badly wounded baddies which he does a lot of for me) and building up capabilities for defensive buffs of stoneskin + phalanx shield. I don't bother with dexterity unless all the other moe useful attributes get maxed. I don't bother to increase willpower on any of my chars as enemies use much more physical than magic damage, especially the missile enemies which are the most dangerous. Resistance to magic can be built up with equipment if there is a need.

Selen (rogue)

Although she claims to be a melee expert, I use her as only an archer in combat. I did a trial with her alt who is said to be the better archer. However she is also a lot more squishy than Selen. As Selen needs to lead through locked doors, and the rest of the time she's number 2 behind Vraes in the party. I also keep her defences beefed up especially in the early part on the game so she can survive quite a bit of punishment. This can come in handy quite a lot. She can also hit multiple adjacent enemies as her skills improve which is helpful. I almost always attack with her first to weaken baddies for others to kill but she's very good a killing enemy missile troops on her own as I prioritise her attributes and equipment etc for dealing damage once I'm happy with her defensive strength.

Kjartan (mage) and Kyera (cleric)

I use these to purely as damage dealers (using only firebolt and holy retribution) with secondary roles as providers of mainly defensive buffs to the whole party. I don't use their offensive debuffs on enemies nor do I use Kyera healing spells. It's more effective to kill threats than to weaken them and any ingame combat healing or mana gaining is more efficiently done with potions.