Party Roles
Healer
It’s certainly possible to play Dark Deity without a cleric, but it’s significantly harder. Clerics are also quite good at other roles, so there’s very little reason not to bring one. Bringing two can be even more efficient: it will let you split the team up (and sometimes you are forced to do this) as well as let you pull the injured cleric back to heal while the other steps up to take on the appropriate foe. This works even better if your clerics have complementary strengths: say Vesta as an inquisitor melee tank and Maren as an acolyte who does magical damage and self heals.
Support
While heal is such a good support skill that it merits its own role, the other support skills are totally worth using. I really like that Dark Deity doesn’t force any class into a pure support role: instead each has at least one utility skill that they bring to the table. Even without expanding the range of these skills they can be a good fallback option or a way to save one of your teammates from being attacked. However, they really shine more if you do choose the class upgrade that specializes more towards support.
Ranged chain in particular will allow you to indefinitely lock down the most dangerous enemy while you take out the rest. Of course it takes one of your teammates out of the fight and you’ll have to protect them, but that’s often quite worth it.
Ranged disarm can dramatically reduce damage taken from dangerous enemies without putting your rogue into the thick of things. This is particularly useful when there isn’t a natural bottleneck to force the enemy to attack you one or two at a time.
Ranged phase can also be quite helpful for positioning. I use it primarily to retrieve player phase attackers who are too squishy to be left in a forward position & a little more range lets the mage do this much more safely. You can also phase your allies through walls/across chasms to shortcut in some places.
Haste can be amusingly stacked on a single character to enable some really long distance plays, but usually the witch hunter (+40% defense) and green knight (+40% fortitude) buffs are the reason to use it. Sometimes you’ll run into enemies with extremely high offense & this buff could save you an injury or help you be more aggressive & thus finish the level faster for more bonus gold. They also can be stacked with buffs like defender/sentinel and aspects like Jahno’s Stupor to reach absurdly high levels.
While extra distance in push can still be useful for shoving allies away from the front line (or slow ones toward it) I haven’t found it as useful.
Player Phase Attacker
Attackers are focused more on power and accuracy than defenses, but defenses are still somewhat important unless the character can kill the enemy in a single hit or avoid retaliation. You will want to either kill enemies near your player phase attackers or have your enemy phase characters move into block the enemy or have support around to phase/push squishy attackers to safety.
Ideally enemy phase and player phase characters will feed off each other: if you can weaken the enemy during enemy phase it’ll be much safer for your player phase attackers to finish them. This will also lead to a small bit of space so you can advance your enemy phase characters a bit further to await the next attack & keep your player phase characters, healers and support safe.
Champions are ideal player phase attackers with their inclination toward one hit kills as are ranged attackers who can stay safer at distance, but there’s a huge variety of builds that can be successful.
Enemy Phase Bruiser
Enemy phase characters dodge or weather attacks on the enemy’s turn and ideally return significant damage to them. Enemy phase is more difficult to plan: you may not be able to move the character to preview combat with each character that may attack it and the AI may not attack who you expect or in the order you expect. Your character holding a bottleneck against a group could also unexpectedly crit and kill three enemies in a row, but get damaged enough that the fourth attacker kills them. To that end, some kind of sustain is highly valuable for enemy phase survival. It’s ideal if enemy phase characters can respond to attacks at both range one and two, however; many of those classes are not as bulky.
The simplest enemy phase characters to build are pure tanks. Classes like sentinel and crusader have good defense, fortitude and hp & can be given aspects to further augment their defenses. They typically won’t do as much damage, though; so you will be relying more on player phase attackers to kill whoever attacks these characters. They also won’t be able to respond to ranged attacks at all. Crusaders may have a little trouble hitting as well, but if you took inquisitor, you can heal someone else on/near the front line and double your accuracy for enemy phase.
Witch hunters can also serve as an enemy phase anti mage tank: you just have to be careful and avoid melee attacks and perhaps strong archers. Use Koeli’s Spirit to let witch hunters (particularly Sophia) swap their high fortitude to high defense and greatly mitigate this weakness. Sloane can play a similar role in one of the higher fortitude mage classes & has the added benefit of being able to retaliate to melee attacks.
Another option is a dodge tank: focus dexterity and speed such that attacks miss you. Patches have significantly reduced the effectiveness of this approach: you can still raise dodge high enough to avoid many attacks, but you won’t reach consistent 1% hit rate without crazy investment in hot bean juice or destroying accuracy with Kitara’s Chord. Thus it’s essential that this kind of tank either have some sustain or also have some bulk for when they eventually do get hit.
Speaking of sustain, it’s worth pointing out the classes that provide it: reverie, astral seeker, acolyte, gladiator and pyromancer as well as Iris’s personal skill. Paired with dodging, defenses or even raw hp to survive, sustain can take an enemy phase character to the next level by enabling them to tank multiple or even all of the enemy attacks. It’s also important that these characters do enough damage in order to heal back and survive more hits as well as reliably hit the enemy. Astral seeker is an interesting case in that the accuracy doesn’t matter: it’s a skill activation that heals you independent of whether you hit and how much damage you do, but only 30% of the time. This isn’t something I’d rely on, but it can be a nice boost if you already have sustain from reverie.