Personality: Cruel, wicked and dominant, Gabriel seeks total control over his own fate. He hates those who judge him, and openly welcomes anyone who would bend their knee and serve. A tyrant, murderer, and enslaver of man and mer, Gabriel may be truly one of the greatest threats to earth until some hero of light extinguishes the dark flame of his life. He cares even not for the suffering of his own minions as he will actively torture his own subjects to ensure a loyalty though fear. The few joys he has are reading a good book, a warm cup of hot chocolate, and nice massages.
Brief History: Cruel, wicked but hurt, Gabriel is a creature of darkness who, tired of those who see him as evil attacking him, has decided to fight back and claim his world for himself, or die trying. In his home universe, he is a terrible tyrant, recruiting evil creatures to perform his bidding which ranges from destroying human civilizations to putting elven forests to the torch, to killing off rival warlocks. He has utilized many strategies to kill of various groups ranging from lizard men, to elves, to even a horde of unicorns which he burnt to death by having his forces surround their forest home, and throwing flaming potions into it until the entire thing was ablaze. However, just as the world was within his grasp, he was whisked away to a new world. What will his new world hold for him?
Universe of Origin: KeeperRL
Equipment
Enchanted Staff: A magical gnarled wooden staff enhanced with magics to make it much more durable, almost like a bar of steel, and who's impact when swung is like a sledgehammer.
Warlock Robes: Gabriel's clothing consists of his robes over a set of standard un-enchanted leather armor. Abilities Combat training: Gabriel has trained in martial combat with the likes of Orcs, Vampires and Ogres. While no master, Gabriel is competent with most melee weapons of medieval times.
Gabriel are able to summon small kobold like demons he dubs imps. Imps are non-combatant creatures, unable to hold their own against a human child in a fight. However, they are master masons and builders, able to cleave through dirt and stone with their claws. Gabriel can summon up to 20 such minions. Such creatures were used in his home realm to build a vast underground complex. They can also build smithies, training dummies, alchemy labs, and even demon gates, portals able to draw in dark beings like succubi, ghosts, and doppelgangers (Horrific monsters who assimilate their prey, in order to steal their abilities.). A list of things they can build can be found here: keeperrl.com/wiki/index.php?title=Con….
Empowered by dark arts, Gabriel is able to cast magic at no fatigue cost of his own. However, each spell has a determined cool down. As he practices his sorcery, he finds himself able to shave off seconds from his cooldowns by his intense training. He has mastered his magical powers about 50%, meaning he could with enough practice cut his cool downs in half. The list of the things he can cast are as follows, with him being able to cast up to Advanced Spells at the moment. keeperrl.com/wiki/index.php?title=Spells
Other:
While the character has no real personality in game, his abilities are fully streamlined. I figured with the small amount of information you're given I could formulate enough of a personality to get the ball rolling, and build one from how things interact with him.
His special material he uses for constructing some of his special buildings is Dark Mana. Dark Mana is gained by killing creatures, or via torture. It is an evil resource most of the time, but can be generated by intense magical study in a library. See Imp construction crew for more details on what Mana can be used for.
For the sake of the RP, characters should be at least semi-serious in tone. Blatant joke characters (at my discretion) can and will be declined. In addition to that, all characters should be from pre-existing works (or, at the very least, ones with relative popularity in some regard). No original characters or what have you.
It is very difficult to justify this character with the given appearance and lack of backstory OR personality.
2. The current cast is more inclined to take out someone who tends towards the actions you have stated here. Even putting aside the arrival of modern military to put him down (which is likely regardless of whether or not the current PCs come), it is very unlikely that the character will be anything more than a one-note villain in their eyes (and, by extension, the RP as a whole). Doubly so given the explicit mention of casual mass murder. The characters in this world have capabilities far beyond what existed in the original work you have pulled this from (I'll touch on this issue in a moment), and pitting them together against one character will unilaterally end with a death on the other side with no casualties.
3. The source material does not apply itself well to the setting of the RP, nor does the blank-slate character you have here. Unlike Robin, who has enough personality from existing in works outside of Awakening (and even then, there remain consistent elements to be referenced from that work), this character can be summed up as a one-note villain out for blood and murder. Even if the character and their powers are scaled up, ten against one, even with mooks, is still a slaughterfest for the latter. It works for the game, but not the RP.
That should summarize my thoughts on the matter for the moment.