*DISCLAIMER*
This is in NO way an attempt to explain whether or not GREE does/will honor bonuses on units which you have more than one of.
Alright, if you are a seasoned veteran of this game, then don't bother reading this. This is addressed to all of those people who still have a difficulty understanding the way the game generates Health Regeneration Time....
Instead of reading the bonus as "-20% health regeneration time" , instead just read it as "20% faster health regeneration"...
for all of you doubters on GREE's math, this should help you to understand.
the initial time it takes to regenerate 1/4 full health so that you can use 1 hit in a boss event is 25 minutes.
let's say you have 1 unit which gives a "-20% health regen"...errr wait! we're calling it "20% faster health regeneration" now!!
what's 20% of 25?....5.
therefore you would have a regeneration time of 20 minutes. now let's assume that this was the regeneration rate for the last boss event in Ireland...
so now you come here to this current PVE LTQ and get the First Strike Tomcat! hip hip hooray!!! another "-20% health reg" oh shoot, nearly forgot!! we're calling it "20% faster health regeneration" !!
so now, going into this new Boss event starting May 24th, what will your new regeneration time be? well what's 20% of 20?....4.
so now in the Madagascar Boss Event, you'll have a health regeneration time of 16 minutes.
notice that we did not do: 20% + 20% = 40% * 25 = 10 minutes, 25-10 = 15 minutes health regen. time.
that is not how it works....
so let's get a bit more complex and say we have 1/6 of the 5% health regeneration bonuses that you can purchase when in a faction...so let's say you're in a really new faction that can't afford a lot of bonuses...
in Ireland, your regen. time would be 5% faster health regen. than 25 minutes.
wha's 5% of 25?....1.25 minutes....so your new health regeneration time would be 23 minutes 45 seconds.....
so when you get 5/6 of the faction health regen. bonuses you should have 25% of 25 minutes = 6.25 minutes= 18.75 minutes for health regeneration, right? WRONG
once again, you must multiply each individual bonus....SO
1/6-----5% faster than 25 minutes 00 seconds = 23 minutes 45 seconds
2/6-----5% faster than 23 minutes 45 seconds = 22 minutes 34 seconds
3/6-----5% faster than 22 minutes 34 seconds = 21 minutes 26 seconds
4/6-----5% faster than 21 minutes 26 seconds = 20 minutes 22 seconds
5/6-----5% faster than 20 minutes 22 seconds = 19 minutes 21 seconds (not 18 minutes 45 seconds)
...so your health regen. time would be 20 minutes 22 seconds....
and if you have all 6/6....
6/6-----5% faster than 19 minutes 21 seconds = 18 minutes 23 seconds
25 minutes * six 5% health regeneration bonuses = 18 minutes 23 seconds
notice this is not equal to 6*5% = 30% faster than 25 minutes which would be 17 minutes 30 seconds.
To all of you who believe GREE doesn't know how to do simple math, I hope you review your arithmetic and quiet down...Sending in tickets for this ridiculous complaint only clogs up their servers and slows down the time it takes for them to respond to meaningful issues...
I hope this sort of helps to explain what is going on with GREE's calculation for health regeneration time.
Good luck in the upcoming Boss Event!
p.s. If you still need help understanding, PM me with ALL of your "faster health regeneration" bonuses and I will write out the math for you.