It would be cool to add a Prestige currency and vendor. While you're playing on a Prestige character a Prestige currency would drop from mobs/bosses, similar to event drops and eternity splinters.
Prestige Points should be character-bound, with the currency amounts showing beside their name in Hero Select and your inventory. You can gain 10 'PP' for each normal level you level-up, not Omega Levels so the bonus PP can't be gained at max level. With Cosmic prestige, you gain 50 PP per level, making it very tempting! PP drop-rates should be considered low since you gain PP through leveling.
Perhaps with each rank of Prestige (Green to Cosmic) there would be an increased drop-rate on the currency, depending on your rank. Also, the vendor would open up new ranks of items depending on your Prestigue rank. I also think the vendor only sells you certain items if you're max level on that prestige, making it much more favorable to get to max.
Alright, as for items I was thinking of things related to the idea of Prestiging, as it's more akin to personalizing a character, or showing your love for that character. Also with the theme of 'leveling'. You know, as opposed to gearing up your character.
This section is more of random ideas I came up with, which might not be in the best interests of the players or developers. So, maybe you guys can figure out better item options (Also, the pricing is not thought out, especially compared to the drop-rates and bonus PP you get from leveling):
Green Tier
150 PP - Random Unique For Your Current Character and Level
500 PP - A recipe to craft a leveling based Runeword.
100 PP - Prestige Rune (These can also drop in the world at a lower drop-rate if you're on Prestige character)
1000 PP - Unlock (either Enchant or Slot upgrade, or heirloom-like gear) that gives 10% bonus XP to your Slot 1 Gear. Buying this recipe unlocks it on all characters crafter or enchanter. That includes the ones bought from the other tiers.
500 PP - The Green Prestige pet sold by Clea.
500 PP - Green flames 'Spotlight' (Ground-based flames) Bound to character on purchase.
Blue Tier
150 PP - Box of Random Runes
1000 PP - Unlock (either Enchant or Slot upgrade, or heirloom-like gear) that gives 10% bonus XP to your Slot 2 Gear.
500 PP - Blue flames 'Spotlight' (Ground-based flames)
Purple Tier
150 PP - Box of Random Relics
1000 PP - Unlock (either Enchant or Slot upgrade, or heirloom-like gear) that gives 10% bonus XP to your Slot 3 Gear.
500 PP - Purple flames 'Spotlight' (Ground-based flames)
Orange Tier
1000 PP - Unlock (either Enchant or Slot upgrade, or heirloom-like gear) that gives 10% bonus XP to your Slot 4 Gear.
500 PP - Orange flames 'Spotlight' (Ground-based flames)
Red Tier
500 PP - Default Current Hero Costume
1000 PP - Unlock (either Enchant or Slot upgrade, or heirloom-like gear) that gives 10% bonus XP to your Slot 5 Gear.
500 PP - Red flames 'Spotlight' (Ground-based flames)
500 PP - Reset story-mode on this character.
Cosmic Tier
5000 PP - Current Hero Stash
5000 PP - Random Current Hero Costume
500 PP - Cosmic flames 'Spotlight' (Ground-based flames)
Think of any better ideas for items or overall? I'll update this thread to contain some better ideas while giving credit to whoever made the idea below: