The Marble Colossus Paladin Set is a very rare set to assemble, being made of four white bag items from an endgame dungeon.
Most of the items in this set is considered to be one of the best items for such classes:
Sword of the Colossus having long range for a sword (4.5 tiles) while also maintaining amazing DPS that always surpasses even the T13 sword;
Marble Seal with very unique ability to give Armored and Damaging to group;
Breastplate of New Life being one of the best defensive armor in the game by giving the wearer a huge amounts of HP while sacrificing some DEF, which is arguably considered a bit less important in endgame dungeons since most of the shots ignore defense;
Magical Lodestone however, despite being one of the best DPS ring in the game, is very controversial. Some people consider it to be the worse version of The Forgotten Crown, due to the fact that it gives +110 HP while Magical Lodestone provides only +6 DEF and +6 SPD in return.
Quite a lot of experienced players tend to use Omnipotence Ring over Magical Lodestone, since they believe it provides all-around better stat, while also fitting the yellow-white color scheme for the entire set.