Astonishing Acid
Tier 1 Finale Damage
Astonishing Acid is a Tier 1 trinket in Grounded. Its effect is Finale Damage. In-game it is described as: "A gland full of seemingly infinite acid. Combo attacks cause it to burst."
A trinket occupies a utility slot — it grants a passive effect rather than raw armor or damage, so it competes with your damage and survival perks for that slot.
The effect it grants is Finale Damage, which is what you are really equipping it for; the slot is better spent here than on a trinket whose effect you will not trigger.
You get it via Analyze Acid Gland.
Verdict: Overall Astonishing Acid is a Tier 1 trinket best used when its Finale Damage effect fits the fight ahead.
A gland full of seemingly infinite acid. Combo attacks cause it to burst.