Help with hero ideas

Hello peoples. I am dangerously close to a demo map on a project I started since I joined this wonderful community. I need help coming up with abilities for a hero in my map: the Spellsword.

Premise: When Dalaran still stood under the human, the elite magocracy crafted unique body guards. These bodyguards were magically bound to a sentient sword. Their magic consists of unique arcane magicks exploiting the unique bond respective to each Spellsword.

Party Role: Damage

NOTE: this is a PvE arena map. All skills are geared towards mobs, not players.

Here are the abilities so far.

Elorre's Hunger (innate): Each strike grants the spellsword 1 mana. Mana cannot be gained through any other method. Burns 8 mana. (Yes, this hero gains mana ONLY through attacking)

Link's Sword*: Hurls a sword at a single target, harming them and interrupting their spellcasting.

Slayer's Wrath: Arcane magic bounces off multiple targets, increasing damage with each bounce.

Vigilant Sacrifice: Restores mana to all of the Spellsword's allies.

Elorre's Awakening*: The sentient sword becomes more self-aware and begins using more of it's inherent power. Increases the amount of mana burned with each strike. Each strike has a chance to deal damage to units in a cone. Each point of mana increases the chance for this to occur.

*this ability could use revision

I will rep those with ideas I end up using.
Thanks ahead of time.

Unless you're using JASS, making skills up is easy because they're mostly based off the WC3 ones, in which there is lots of diversity though. Here's an idea though:

Unleash Spirit: The spirit linked to the sword is expelled from the blade toward the target, unleashing whatever effect the spirit harbors. I.e Fenix Blade expels a glowing fenix that burns the victim, Wolfbane expels a savage wold that violently bites the target.

That is, assuming you're having multiple 'Spellswords'.

I'm trying to come up with fun, inventive, not-overly-complicated spells. So coming up with ideas can be half of it.

Actually, the map is made to have unique heroes (only one) to promote group diversity. Although having some kind of possession move would be cool. As of now his magic is lightning/arcane. All my heroes have a color theme to them that is present also in their spells.

Well then he could have some sort of animal that represents lightning... how about a snake? It strikes very quickly.

Erinyes' Edge - The Spellsword channels mana into his blade, strengthening it into a weapon with a sharpness and strength unmatched by lesser kin of the swords wielded by the Spellswords. Each blow drains a small portion of mana in exchange for ruthless damage. (Orb of Annihilation or Searing Arrows)

Paralytic Touch - The Spellsword doesn't hold foes in the traditional sense of the magical application, in which the target has to be bound head and foot to prevent a foe from moving. Instead, because of having to make do with as little mana as they can manage, they use a charge of electricity just strong enough to cause either uncontrollable spams in an organic foe or temporarily disable the inner workings of magical or mechanical foes. To make the most of this technique, the charge is usually applied at point blank range. (Entangling Roots)

Elorre's Taint - As the swords grows in strength in the heart of conflict it begins to radiate, corroding any foes down to a husk of what was. As the Spellsword matures in skill, this ability eventually become the most feared for the finality that follows. In those which the talent has freshly manifested, it is merely akin to poison. (Disease Cloud or Incinerate or Slow Poison or Unholy Aura (with negative values))