This is an amazing update idea and I really look forward to however it is put into game!
So I've thought about this alot and they way that I would most like to see it implemented is by unlocking one piece at a time, counting kills from every boss in the collection log. Then, for simplicity, each boss will be given a multiplier and each tier will require 100 kills * multiplier for all bosses, plus 2000 total boss kill count which will be the sum of all boss kills. With the dummy multipliers I put in place the total number for each tier would be 1326 specific kills. So for each tier:
TIER 1: GLOVES
100*(boss specific multiplier) kills per boss
2000 total boss kills
TIER 2: BOOTS
200*(boss specific multiplier) kills per boss
4000 total boss kills
TIER 3: HELM
300*(boss specific multiplier) kills per boss
6000 total boss kills
TIER 4: PLATELEGS
400*(boss specific multiplier) kills per boss
8000 total boss kills
TIER 5: CHESTPLATE
500*(boss specific multiplier) kills per boss
10000 total boss kills
So this is the list of bosses that I would personally want to add. This does not include barrows, slayer bosses, or gorillas. I don't personally believe that they should be counted, but I am of course open if other people think they should. Please find the specific multipliers that I put in place for each boss as a place holder, again the total right now is 1326 specific kills.
0.15 - Blink
0.25 - Chaos Elemental
1 - Commander Zyliana
0.5 - Corporeal Beast
3 - Dagannoth Kings (1 for each)
1 - General Graardor
1 - Kree'arra
1 - K'ril Tsusaroth
0.5 - Kalphite Queen
1 - King Black Dragon
0.25 - Nex
0.5 - Queen Black Dragon
0.25 - Tormented Demons
0.05 - TzTok-Jad
0.01 - Har'Aken
0.25 - Graetoriax the Unbroken
0.25 - Harbinger X'Rul
0.25 - Nomad
0.05 - WildyWyrm
1 - Venenatix
0.5 - Vorkath
0.5 - Zulrah
As for the armour itself, these are the specific perks that I would personally like to see:
Tribrid armour
0.2x reduction in instance cost (and GWD room entry) per piece worn
+4 prayer per piece worn
0.03x increase in damage to bosses per piece worn
0.03x increase in drop rate from bosses per piece worn
While any piece is equipped (or all the time after tier 1 is unlocked); add total boss kill count to right click player examine text in chat
Access to different tiers of PVM shop that include things like rocktails, overloads, super antifires, enchanted bolts, etc.
Thank you for reading, very excited for this to roll out!
Gabriel