Rubick

Rubick the Grand Magus is a ranged Intelligence hero best known for his ability to copy the spells of his enemies and use them as his own. Although he is mostly played as a support and is extremely fragile the entire length of the game, he can still prove to be one of the most influential heroes if he utilizes good positioning and well-timed usage of his ultimate, Spell Steal. Spell Steal allows Rubick to cast an enemy hero's most recently used spell, giving him supreme versatility throughout the game. By stealing the right abilities, the Grand Magus can aid himself and allies by casting crippling disables, applying curses, unleashing powerful nukes, disorienting the enemy team, supporting his allies with buffs, escaping from rough situations, or even enhancing his own physical attacks. His other abilities are just as worthy of a Magus: Telekinesis lets Rubick magically lift an enemy into the air, rendering the target helpless and vulnerable, before hurling the lifted enemy to the ground up to a short distance away and stunning nearby foes on impact. Fade Bolt blasts enemies with a stream of arcane energy which bounces to all enemies nearby, dealing damage and reducing their attack damage. Null Field is a passive aura, which grants himself and nearby allied heroes bonus magic resistance to shrug off magical assaults. Rubick's versatile ability-set and his infamous Spell Steal make him a flexible and powerful hero that can work in any lineup although he does suffer from long cool-downs and the surfacing predictability of his ultimate.

Tips

 * Both his Telekinesis and his Fade Bolt have a high mana cost. Try to be conservative of your mana early on until you can grab some items such as a Void Stone or a Bottle to accommodate his somewhat high mana costs for the early stages of the game.
 * As Rubick during the mid and late-game, stealing key teamfight spells and keeping yourself alive should be your main goals. Your spell steal only has a .1 second cast time and high cast range, so quick fingers and fast reaction time will give your team with a huge advantage.
 * Also, keep in mind what abilities your enemies have, and what you plan to steal, so that you can be ready when enemies cast important spells.
 * Fade Bolt harassment makes you a powerful midlane hero, since the attack damage reduction secondary effect also makes it more difficult for your opponent to lasthit properly.
 * Against heavy magic damage teams, you may have to invest an early point on Null Field since its percentage reduction will scale into later stages of the game.
 * Although a great disabler and potential initiator with the right items, Rubick is still frail with the proper focus on him. Stay back as much as you can to avoid unnecessary damage and keep casting and stealing spells!
 * Be specially careful against Void. Stealing Void's ultimate may turn the tide against your team, since he will not be locked by Rubick's Chronosphere. If you steal it, try to use it when Faceless Void is either dead or far away.
 * Almost all of his spells, including the spells he steals, have 0.1 casting time. So spells such as Earthshaker's Fissure and Leshrac's Split Earth will cast immediately. Use this knowledge to your advantage. (Although any spell that require him to channel such as Enigma's Black Hole or Sand King's Epicenter will still require Rubick to channel).
 * If you are in a side lane, try laning with partners that have powerful nukes, attacks or stuns even in the early game. Heroes such as Juggernaut, Bane, Zeus, Wraith King, Chaos Knight, Luna and Ogre Magi are perfect, as target-point abilities can be used on enemy heroes Rubick is holding in mid-air.
 * Rubick is also a good partner for Heroes with a difficult to land stun/nuke. Kunkka, Alchemist, Lina, Jakiro, Leshrac, Ancient Apparition or even Invoker with his Sun Strike will greatly benefit from your Telekinesis. Also note that you can steal those abilities to disable enemies yourself for a long duration.
 * Morph Strength Gain is a good spell to steal as it allows you to morph all Agility into Strength permanently, even if you lose the ability. However, it is important to never go full Agility.
 * Stolen Psionic Traps do not get destroyed when you lose the spell, and can be very useful to set up permanent vision of rune spots, Roshan, ancient camps and other key spots on the map. If you lose this spell and steal it again, you may still set 5/8/11 traps (depending on the level of the stolen spell) without destroying the other traps. This can give your team a great vision advantage since the number of traps you can set is virtually limitless.
 * Anti Mage's Blink is a great spell to steal since it gives Rubick the mobility he needs, and has lower cooldown compared to Blink Dagger. Having both will give Rubick a tremendous escape/initiation mechanism! Queen of Pain's Blink and Weaver's Shukuchi are similarly useful.
 * A stolen Meat Hook can be extremely useful to initiate teamfights. Most enemy heroes won't expect to be hooked, which causes them to be less careful about their positioning. The same goes for Mirana's Sacred Arrow.
 * Spell Steal cannot steal passive abilities, but stealing Slark's Shadow Dance will give Rubick the passive part of the ability too.
 * Be careful when stealing spells from Keeper of the Light. If you steal a spell used with Spirit Form right after its duration ends, the spell will be inactive!
 * You can convert creeps using Chen's Holy Persuasion, but all converted creeps die once you lose the spell. The same goes for Lone Druid's Spirit Bear.
 * Storm Spirit's Ball Lightning, when stolen by Rubick, has its manacost adjusted for Rubick's mana pool.
 * A stolen Broodmother's Spin Web will give Rubick the invisibility and everything else. It does not interact with Broodmother at all.

Trivia

 * In both DotA and Dota 2, he is the son of Aghanim. He also possesses an imitation of Aghanim's scepter as one of his cosmetic items.
 * If Rubick acquires Tusk's Walrus Punch ability, he will cast it as a projectile on the target by throwing a spinning, projectile form of himself toward them. When targeted on Tusk himself, the text "Sucker Punch!" will be displayed, in green colors. The caption will be changed to "Stolen Punch!" when hitting creeps and other heroes.
 * If Rubick steals Lycan's Shapeshift,  Undying's Flesh Golem, or  Dragon Knight's Elder Dragon Form, he will transform into the same model the respective abilities use, though slightly smaller in scale compared to the original owner's. Rubick still retains his ranged attack, able to use any of the passive components the ability possesses (like Critical Strike or Corrosive Breath, for instance). Stealing  Alchemist's Chemical Rage does not change Rubick's model (unlike in DotA), but rather just adds a purple hue and effect onto him. He does still gain the ability's passive attributes like the attack speed increase and HP regeneration.
 * Rubick is named after Ernő Rubik, the Hungarian inventor who designed the "Magic Cube" (most commonly called "Rubik's Cube"), a popular combination puzzle. His response, "Now, where's my cube?" is also a reference to Rubik's Cube.
 * In DotA, Rubick couldn't steal several spells due to technical limitations. The complete list can be found here.
 * If Rubick activates a stolen True Form ( Lone Druid's transformation spell) while in the process of stealing another spell, he will permanently remain in True Form mode, earning the additional buffs and melee range, all while keeping his default abilities. He will only revert back to his default self upon deactivating the ability, or dying.