Vanilla Changes
The Shadows of Abaddon mod modifies some aspects of Terraria, revolving around balance changes and access to the mod's content through vanilla NPCs.
Item Changes
Destabilized Chaos and Dissonant Harmony
Destabilized Chaos and Dissonant Harmony are balance changes for the 
Rod of Discord and the 
Rod of Harmony respectively. In either case, they can only be used while Chaos State is active outside of boss fights and cannot be used in restricted areas. It also activates Chaos State for 12 / 10 seconds upon usage of their respective item while a boss is alive.
Icarus' Folly
Icarus' Folly is a balance change for the 
Soaring Insignia. During boss fights, the infinite flight time is replaced by a 50% increase to flight time. However, flight is still possible after flight time reaches 0. In exchange, the player gets the Icarus' Folly debuff, which decreases damage, flight speed and increases damage taken proportionally to the amount of time the player stays in the air after all flight time has been used.
NPC changes
Nebula floaters take 10 times more damage than normal because they are really annoying.
| Game mechanics | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Combat | Minions • Ability | ||||||||
| Environment | Events • Music • Status messages | ||||||||
| Items | Consumable • Crafting stations (By Hand) • Drops • Rarity • Modifiers | ||||||||
| Game | Game controls • NPC names • Vanilla Changes | ||||||||
| Player | Buffs and Debuffs • Death Prevention • Defense | ||||||||
| True Mode | Superarmor and Hyperarmor • Aggression • Damage Falloff • Diminishing Returns | ||||||||
| Boss Damage • Polarize • Accuracy • Suppression • Crit Damage | |||||||||