Builds are built around a "Primary" skill.
So I'm figuring out what I think is a fundamental of making builds in Grim Dawn, and I think I need to put it in a little presentation so people who know better can check my work, and people who as inexperienced as I am can learn alongside me. Please bear with me as I try to make sense of this.
So on any Grim Dawn build, you are generally going to have one, singular "Main" attack that is the one you spam when you've got nothing better to do. It's the skill on your Left Mouse Button, most of the time. The most basic example of this is the default attack, obviously, but by my reckoning there are about 3 different categories of skills that can serve this role, and I'm hoping to get some help understanding which skills synergize with which abilities, because I know some skills only synergize with basic attacks and their replacements.
The most obvious set are the skills meant to be Defaults Attacks: Cadence, Fire Strike, Savagery, Righteous Fervor, and from the look of things, Onslaught from the upcoming Berserker.
These are generally, functionally better versions of your default attack. Sure, they eat a bit of mana on use, but it's a small enough ammount that you're never gonna run dry using these, at least in my experience. If someone has a build where that's a legitimate concern, I would genuinely be interested and impressed to see it.
These work with passives that talk about default weapon attacks with a % chance to activate, right? Inquisitor's Bursting Rounds, Chilling Rounds and Storm Spread, Shaman's Feral Hunger and Upheaval, Nightblade's very long skill tree branching off from Dual Blades, etc. I've run a Fire Strike Purifier, and I'm 90% sure it works that way, but if I'm wrong, now would be a great time to tell me so I don't embarass myself any further.
Then, you get spammable Spells, and spells that can become Spammable in the right build - Panetti's Replicating Missile is probably the most iconic of these, but the likes of Tremor Forcewave, Blackwater Cocktail, Frenetic Throw Phantasmal Blades, Devouring Swarm, Thunderous Primal Strike, Dreeg's Evil Eye, and apparently Vire's Might with the right items, can all be turned into your primary skill if you're doing more of a caster build, yes?
Based on the tooltip for Thunderous Strike, which is pretty clearly written to try and explain this exact dyanmic to new players, these don't trigger passive effects like the default attacks do. They are classified differently, and are a much more mana-intensive primary casting option.
So what do they synergize with? Shaman Specifically seems to be where these two types of abilities are in tension, so let's focus on that class - Brutal Force adds both flat damage, and percentage boosts. Does it only add those to default attacks, or does it also boost Primal Strike? It says it's for 2-handed weapons specifically, but if I'm holding a 2-handed weapon as I cast Devouring Swarm, does it buff that too?
The part I'm looking for help wrapping my head around is how I should categorize passives to know what builds they would and wouldn't help, I guess. Similarly, toggleable buffs like Mogdrogen's Pact, Solael's Witchfire, Iskandra's Elemental Exchange, and Flame Touched I feel like I usually avoid, because I don't know what abilities they do or don't apply to. Is it just everything? That feels like it would make sense of why the caster classes get these abilities, but I'm not sure.
Of course, the split I'm placing between abilities with cooldowns and abilities without is entirely a functional one based on the fact that you probably don't have a use for two no-cooldown abilities, and you're better off having one primary, and one or more secondaries that you click whenever they're off cooldown, which is why Blackwater Cocktail, Dreeg's Evil Eye, and a few others being able to be modified to be stronger with a cooldown or spamable without makes them useful and versatile skills. So presumably whatever buffs those spells will also buff spells that always have a cooldown, like Trozan's Sky Shard, Aegis of Menthir, or even summons that don't scale based on pet bonuses, like the Shaman's Totems.
That's probably enough rant for me to get useful feedback. Anyone willing to help me get a clearer picture of what works well together?
Edit: Oh, and where does Casting Speed factor in? I guess that's the other important question - which skills benefit from Casting Speed, and which from Attack Speed? Do some benefit from both somehow? Or neither?