All Majesty Original hero spells save for the Teleport ones have been incorporated into the new spell system. Also managed to finish up expanding the Rogues Guild functions.

0.05 Changelog

Spell Changes

Generic
Power Shock
-Cooldown changed from 15 seconds to 6 seconds.
-Range: 60% of Max Cast range.
-Mana Cost: 4

Flame Shield
-Magic Resistance gain changed from 20 to 8 + (Intelligence / 6).
-Armor gain changed from 4 to 1 + (Intelligence / 10).
-Duration changed from 20 seconds to 14 seconds.
-Cooldown changed from 30 seconds to 12 seconds.
-Range: 50% of Max Cast range.
-Mana Cost: 6
-Can cast on nearby allies.
-Does not naturally stack.
Will cast on the closest allied target if the caster already has the effect on himself.

Regenerate
-Heal Strength has been removed.
-Health Regeneration Rate is used in place of Heal Strength.
-Increases Health Regeneration rate by 0.50 + (Intelligence / 8).
-Duration changed from 8 + (Intelligence * 0.25) seconds to 8 seconds.
-Cooldown changed from 24 - (Intelligence * 0.25) seconds to 14 seconds.
-Range: 50% of Max Cast range.
-Mana Cost: 7
-No longer stacks.
-Can cast on allies.
The new Health Regeneration system is much more powerful than the game's built-in healing, so the buff of Regenerate will be far more prominent.

Priestess
Drain Life
-Cooldown changed from 2.5 seconds to 2 seconds.
-Range: 67% of Max Cast range.
-Mana Cost: 2

Animate Skeleton
-Cooldown changed from 7 seconds to 5 seconds.
-Range: Self.
-Mana Cost: 7

Control Undead
-Cooldown changed from 5 seconds to 4 seconds.
-Range: 67% of Max Cast range.
-Mana Cost: 8
Bug where multiple stacks of the charm icon and buff could occur has been resolved.

Wither
-Duration changed from 8 + (Intelligence / 4) seconds to 10 seconds.
-Cooldown changed from 25 - (Intelligence / 4) seconds to 12 seconds.
-Range: 70% of Max Cast range.
-Mana Cost: 5
-No longer stacks.

Building Changes

Rogue's Guild
-Now sells Dart Sentries when your kingdom has at least two Level 2 Rogues Guilds
-Heroes that enter Rogues Guilds to poison their weapons may now also purchase a Dart Sentry to deploy in combat.
-Dart Sentries cost 45 gold and heroes can carry only one at a time.

Deploy Dart Sentry
-Creates a Dart Sentry near the target. The Sentry lasts until all darts are fired or its duration runs out.
-Ranged Attack value has been set to 45 + Artifice.
-Attack Range value has been set to 120 + Artifice.
-Attack Period has been set to 1.5 - (Artifice * 0.01) seconds.
-Deals 2 + (Artifice / 10) damage per successful strike with a dart at the closest enemy unit.
-Dart Count: 10 + (Artifice / 5).
-Duration: 60 Seconds.

Now that nearly every part of the spell system has been stress tested by porting over the old spells, I will be setting aside time to develop and implement a skill tree system for heroes in Majesty. As with their Attributes, they can choose and develop a particular set of spells and abilities to eventually be a jack of all trades or a master of one, which includes learning new skills specific to their class as well as leveling up their current spells, even leveling up Class and Generic Spells learned from the Library.

For example, a newly recruited Priestess will be able decide at level one whether to learn Animate Skeleton or Raise Zombie spell, meaning that even at level one, heroes of the same class type will already be different from each other in a noticeable way.

I don't have a particular hero in mind for prototyping this system for, but I would like to have at least one hero with at least one skill tree completely developed by the next release. So I'll take suggestions for the first hero you'd like to see have a fully developed and implemented skill/ability tree for, which will involve somewhere around 10 - 12 new spells/abilities for that hero.

Up Next: Experimenting with Hero Decision Trees. Implementing Shrine auto-structure.