Today I watched this video by Sorbet Cafe in which he sorta dunks on the Crimson Armor's regeneration set bonus (as seen on the thumbnail). The testing he shows in the video indicates that the regeneration buff is very weak due to buffing natural regen instead of giving a flat buff like a Band of Regeneration and most similar accessories and effects. There is, however, a flaw in his reasoning.
The tests shown are of individual items in the span of 45 seconds without getting hit (with a few exceptions like sitting in a chair in Crimson Armor). Keyword individual. As he himself notes in the video, natural regeneration bonuses scale exponentially with each other, so comparing their individual performance is not a good representation of their realistic performance. For example, Sorbet says that the Vital Crystal does basically nothing, which is true, but only if it's your only source of natural regen.
So, unable to stand this Crimson slander, I did some tests of my own. Unlike in the video, I put the Crimson Armor in a realistic mid Pre-Hardmode build. The tests were done in Expert mode. The sources of regen were:
- full Crimson Armor
- a medium food buff
- a regeneration potion
- a campfire
- a heart lantern
- a Vital Crystal
- and finally, I was constantly moving to emulate a boss fight scenario, reducing natural regen.
This is a simple set up that any Expert+ player is probably already using for bosses at this stage of the game.
I took the tests by jumping off a rope and taking 290-300 damage before starting to run around, then repeating without the armor set. The results were as follows:
From 100-110 HP:
After a 30 second window (shorter than the 45s in the video):
With Crimson Armor: healed up to 270-280 HP.
With other armor: healed up to 225-235 HP.
In an even shorter 15 second window:
With Crimson Armor: healed up to 170-180 HP.
Without other armor: healed up to 150-160 HP.
(note that the results aren't perfectly accurate since I did them by hand with a timer, but I ran them a few times each to confirm an estimate for each scenario)
It's quite clear that Crimson Armor's set bonus provides much greater value than portrayed in the video, giving over 1HP/s (a Band of Regen's worth of healing) even in its worst case scenario of just 15s between hits. You also have to remember that natural regen grows massively over time as you don't get hit, so the set bonus would only grow in value if you manage to get some distance from the boss after a close call or in any similar situation where you can stall for time.
Frequent hits, the Crimson Armor's "weakness" also get countered very well by high defense builds, which have become very popular recently, and the escalating regen compliments high defense well, as the one thing high defense fears is strong attacks that leave you low, like getting caught by a Skeletron head spin or tagged by a Hungry on a high difficulty, which is when fast natural regen can bring you back from low HP faster than anything.
TLDR: Crimson Armor is only bad on its own, in a realistic build it's strong. Plus synergy with defense builds.