Kind of got this idea from glyphs from WoW. I think it would be neat if players can customize their characters a bit by modifying what their skills do.

Essentially what it would allow a player to do is improve a skill in some way while weakening it in another, or change how it functions. These can be changed at any time outside of combat (maybe with reagent cost), and only a certain number of them can be enabled at a time.

Examples:

Arcanist/Scholar/Summoner
Adloquium: Adloquium's barrier is 25% stronger, however its effect is no longer doubled on criticals.
Selene: Increases the effect of Selene's Fey Glow and Fey Light to 45%, however both skills now share the same cooldown.
Ruin II: Ruin II no longer Blinds the enemy.
Fester: Reduces the damage of Fester by 50%, however it no longer consumes Aetherflow.
Summon (Summoner): Summoned pets now appear as either an Emerald, Topaz, or Ruby Carbuncle.

Gladiator/Paladin
Savage Blade: Savage Blade now combos off Riot Blade instead of Fast Blade.
Bulwark: Bulwark causes damage blocked to be reflected back at the attacker, however it no longer increases block rate. Damage cannot exceed 10% of your Max HP per hit.
Fight or Flight: Reduces the cooldown of Fight or Flight by 30 seconds and reduces increased damage dealt to 20%.

Marauder/Warrior
Mercy Stroke: Increases potency to 300, however healing received from killing blows is reduced to 10%.
Berserk: Berserk no longer pacifies when the effect ends, however the effect is reduced to 35%.
Bloodbath: Increases Bloodbath's conversion to 50%, however the duration is reduced to 10 seconds.

Ideas? Thoughts?