I know this is a huge bump, but as of 2014 the Loyalty items are stronger.
(Viking clan)
Gold Tier
Surtr the Flame Giant - 4000 LP - 240 attack, 240 defense
Chariot of Fire - 4000 LP - 230 attack, 250 defense
Netherfire Sword - 4000 LP - 250 attack, 230 defense
Platinum Tier
Zephyr Robes - 4500 LP - 238 attack, 262 defense
Fanblade - 4500 LP - 262 attack, 238 defense
Windmaiden - 4500 LP - 250 attack, 250 defense
I know nothing about the diamond or alexandrite tier.
And about the loyalty percentage bar. It has nothing to do with how much LP you have. I have 2985 LP(haven't spent anything).
I am in gold tier. Level 2041.
If you think about it, "loyalty points" are really just points gained from how loyal you are to KANO.
About when I just reached gold tier, I thought of buying some favor points(like 25 or so). And I did. Right away I was given 1% of the loyalty bar.
I later on went inactive for a while, and when I came back, it was at 0%.
Conclusion: The loyalty percentage bar is NOT based on how much LP you have. It increases if you play the game daily(or often without large gaps in between). It will increase faster if you buy FP.
It decreases if you are inactive for a long time.
Basically they reward you with more LP and a new tier if you stay loyal to them and play it often. (Because it benefits them by having traffic on the game).