Karax by Pickly

Level 1:

Observer: Karax can place an observer. Acts like a scouting drone, but is invisible.
Absorbing Shield: Quest. Absorb damage with plasma shield. reward. Can summon another shield battery. When this battery is summoned, reset the quest.
Piercing Strike: Orbital strike does extra damage to structures.

Level 4:

Emergency repair: Repair drone and Shield battery for more when target's health is low.
Protected drones: Repair drone and Shield battery heal for more when they and their target are out of combat for 3 seconds.
Thermal strike: Orbital strike leaves a damage field on the ground.
Lingering shields: Instead of disappearing when its time is up, plasma shield decays over 2 seconds.

level 7:

Shield Upgrade: Plasma Shield reduces autoattack damage by a fixed amount.
Hardened Shield: Plasma shield takes at most 1/5 (or so) of its max value as damage from any one spell or attack.
Purifier based weapons: Karax, and Karax's repair and shield battery targets, deal extra damage to minions.
Mercenary Lord: Mercenaries do more damage when near Karax, amd receive extra healing from his skills.

Level 10:

Reaver: See above.
Reconstruction Beam: See above.
Khaydarin Monolith: See above.

level 13:

Shielding battery: When shield battery switches targets, give the new target a small shield.
Smart shielding: Plasma shield increases healing from all sources.
New Templar: When Karax damages a hero with orbital strike, deal extra damage with the next 2 autoattacks
Time Stop: Quest. When heroes recently damaged by orbital strike are killed, the quest gets credit. With a certain amount of heroes killed, karax may use time stop. The skill acts like orbital strike, but channels in 1 second and stuns for 2. Once used, the quest resets.

Level 17:

Double Shield: Plasma shield effects a second nearby ally, prioritizing heroes, for a smaller amount, untalented except for ultimates.
Khaydarin core: Increases the range of Karax's passives and buildings.
Solar Lance: Karax gains 5 casts a ofsolar lance. Instantly Deal a large damage in a targeted line (Think like Probius's null gate ultimate) Once these casts are used up, karax cannot gain them back.
Purify: 30 second cooldown. Stun keep and Forts for 5 seconds, turn towers against their team for 5 seconds. 45 second cooldown.

Level 20:

Solarite Constructor: Reavers can shoot up to 10 shots, and last up to 30 seconds.
Improved Defenses: Khaydarin monolith attacks stun the target for .5 seconds.
Fully Ignited Core: Reconstruction beam lasts 30 seconds, can be retargeted, and automatically retargets itself if the current target dies or is fully healed.
Instant Strike: Karax no longer needs to channel orbital strike. The strike comes 2 seconds after being called, not 4.
Guardian shield: For 5 seconds, Karax gives nearby allies 50 armor. 60 second cooldown.

Interaction

Karax: That is a crude device you are using. May I suggest some improvements?
Gazlowe: Eh, whateva, gets da job done.

Karax: A long range projectile device. Crude, but powerful.
Hammer: Its called a siege tank, no-mouth! Greatest machine ever built.

Karax: I think I can guess your device's function, but the shape unusual.
D.Va: It's a rabbit. None of those on Aiur.

Karax: A terran Goliath, the nexus works in fascinating ways.

Tychus: Somethin tells me you ain't much of a fighter.
Karax: I was not a templar until recently, but the war with Amon has trained me.

Karax kills enemy

Undead: Such a being should not be possible. I must investigate.

Artanis: i am now a templar, and I shall fight as one

Probius: Something has changed in that probe's programming

Diablo: Terror will never defeat a templar.

Enemy kills Karax

Tychus; All them fancy devices can't handle a plain old minigun.

Brightwing: Such pretty robots. *laughs*

Nova: "You weren't cut out for battle anyway"

Johanna: "A smith should always avoid combat."

Silly Quotes

"This nexus appears to violate all laws of the universe, We have much to understand."

"I could almost understand this place it is was.."

"A fun activity, programmed on a computing device, used for the entertainment of a terran like species."

"It would explain the unusual creatures I have met here. But that is merely speculation."

"Even primitive terran engineering can match us in battle. I have never understood how."

"Why haven't protoss thought of medics? It would save our warrior's lives, and we can ill afford to waste them."