Hello, This is a guide for Astronarch, I just beat the game will all the achievements and Max leveled all characters, I kept a doc going for my notes (When I come back in future patches), thought I would post it here as some might find it useful. This is all my opinion only.

Wrote for version: 1.5.3

Role/Orbs/Build/Items/Blessings/Nodes are listed in order of how good they are (Best first)

Party Composition: Any works, game is beatable on Corruption 20 (Including Omen of Loss) with random heros, recommend a Healer and Tank by act 2.

Blessings: The Magician (MP Costs) Blessing unless healer is Bloodmage then Temperance (HP), If I need ancient items then Wheel of Fortune, The Chariot (monsters cannot be found in events), King of Wands (Merchant price reduction), Anything else

Events: Act 1 get upgraded items and take debuff if not before elite/boss fight, Act 2 fight for Prized Scimitar and/or Regalia, Act 3 interstellar seller sacrifice vitality.

Lanes: Act 1 I take bottom lane, Act 2 + 3 I take mid lane

Elites: I take all elites, if I don't kill at least 2 elites in Act 1, I restart

Node Priority: Elites, Normal Fights in First Half of Act 1, Shops when over 120 gold, Question Marks, Normal Fights

Top Characters (Details Below)
Top Healer: Cleric, Druid
Top Tank: Druid, Juggernaut/Bloodmage
Top DPS: Ronin/Outlaw
Top Buffer: Alchemist
Top 5th Character: Assassin

Format (Sorry pasted from spreadsheet)
Role:
Tier:
Orbs:
Notes:
Items:

Notes:
Check items section to see which items are in each set.
Tier: S = Can Perform more than 1 build at top tier, A = Top Tier at build, B = Good, C = OK, D = Bad
Orbs: Not listed in Orbs below if I think the money from selling is more worth than the upgrade

Alchemist
Buffer/DPS
A
Blue
Easy to Gear, best buffer, amazing for long fights
Bandit Hood, Spriggan Sickle, Any Attack Speed Items or DPS Set

Assassin
DPS/5th Character
A
None
Good dps, great 5th character, does not need orbs to be good
DPS Set

Bard
Healer/DPS
A
Red
Blue Orbs if Prized Scimitar, good healer, heals all
Caster Set or Prized Scimitar/Party Member with Flying Fury

Berserker
DPS/Off Tank
B
Blue
Low HP, Needs items to be good
Onion's Guard or Prized Regalia, Warlord's Burden, Any Attack Speed Items

Bloodmage
Tank/Off Tank/Healer
S
Blue
Red Orbs if Ancient Codex, Great Tank with Ancient Codex, Ok Healer
Ancient Codex, Saint's Vow, Plate of the Fallen (Main Tank), Charging Pylon (Off Tank)

Brawler
Off Tank/DPS
C
Blue or Red
Cannot Tank Act 3 very well (compared to other options), not as good caster as ronin
Tank Set or Caster Set

Cleric
Healer/Debuff Removal
S
Red
Best Healer + debuff removal
Caster Set, Charging Pylon

Druid
Tank/Healer
S
Blue + Red
Great Tank + Healer + DPS and Buffer
Tank Set, Tower Shield

Fallen
Buffer/Off Tank
C
Red
Ok buffer if you have a comp with red orbs free, good off tank with Helm of the Mad King
Caster Set or Tank Set

Fiend
5th Character/Off Tank
B
Blue
Great 5th Character if you have blue orbs free
Prized Regalia, Tank Set, Party Member with Flying Fury

Frostmancer
Debuffer/Off Tank
A
1 Blue
Amazing debuffer with Ancient Codex
Ancient Codex, Saint's Vow, Mana Spring Amulet

Gladiator
Off Tank
D
Blue
Needs a lot of setup to work
Tank Set, Realm Tooth

Illusionist
DPS/Off Tank
D
None
Needs a lot of setup to work, low DPS, poor tank
Onion's Guard, DPS Set

Juggernaut
Tank/DPS
S
Blue
Best Tank, good DPS
Tank Set

Outlaw
DPS/Off Tank/5th Character
A
Red
High poison (if he gets a few actives off you can win even if he dies), can off tank then go hidden Caster Set, Party member with Spriggan Sickle

Paladin
Tank
D
None
Bad Passive, Active very high MP
Tank Set

Pyromancer
DPS
A
Red
Needs 1 red orb and some burn items to get going, big burst
Searing Edge, Bound Elements

Ranger
Tank, 5th Character
B
Blue
Good when you get multiple tower shields and have blue orbs and room
Tower Shield, Any Defense Items

Ronin
DPS
S
Red Or Blue
Low cost good damage active.
Bleed build can be awesome with Scythe
Caster Set / Attack Speed + Scythe

Warlock
Healer/DPS
C
Red
Takes a lot of gear to get going as heals are based on attack
Caster Set

Wildmage
DPS
D
None
Passive does not provide much protection, Active does not do much damage
Caster Set

Items: All not listed in sections below I think are not worth and just filler until you get better items

Caster Set:
Main Set: Symbiote/Headdress of Fury/Mana spring Amulet/Tundra Talisman/Lich Wraps or Any Starting MP Item
Alternative 1 Ancient Codex/Warlords Burden/Mana spring Amulet
Alternative 2 Symbiote/Lich Stick/Starry Songbird
Alternative 3 Elaborate Manuscript/Symibote/Any Starting MP Item
Starter Items Lich Wraps, Maiden's Mirror, Brain Sage, Crystalline Protector

DPS Set: (Don't Stack below 0.5 Attack Speed, You want at least one of the Other items below)
Priority Attack Speed Items Zephyrs Pendant, Shard of the Deep, Warlords Burden, Bandit Hood (for 5th character), Any Attack Speed Items
Other Items Scourge of the Wastes, Mask of Torment, Ragnarock, Realm Tooth
Starter Items: Fenrir's Bane, Flying Fury, Stiggian Sickle, Necrophage, Cobra's Reach, Bound Elements, Searing Edge, Soothing Star (With no Poison + Bleed in team), Serrated Ripper, Impaler, High Elf Claymore

Tank Set:
Ultimate Tank DPS Set Helm of the Mad King, War Mage's Greatstaff, Onion's Guard/Plate of the Fallen
HP Tank Set Saint's Vow, Oaken Knot, Holy Charm, Plate of the Fallen, Any HP Items
Starter Items: Defense Gauntlet, Mystical Fruit, Reverberating Bulwark, Noble Ward, Reckless Dueling Shield, Hero's Sigil, Restoration Wrap, Odd Bean, Holy Charm, Frozen Shell, Safety Slime, Bone Spike Armor

Reverie Totem Set: (Good when you have lots of casters in party)
Main Item Reverie Totem
Supporting Items Prized Scimitar (on another character), Seed Relic, Colossal Smasher, Zilla's Tempest

Items/Combos that could work but take too much build up or not enough payoff compared to taking other items: (Still work great on lower corruptions)
Hero's Sigil + Bouncing Buckler + Gladiator
Phantom Band + Crown of the Banshee
Reckless Dueling Blade + Crown of the Banshee
Giants Club + Saint's Vow/Gladiator
Regenerating Core + Fiend
Vampiric Guard + Enchanter Chain mail
Life Giving Chamber + Gladiator

Again items + orbs I left out I didn't find were good enough to pick if I had a choice (my opinion)

Let me know if you find any other items/builds that work great on corruption 20 and I will test them out :)