Invoker

Invoker is an almighty caster Intelligence Hero, considered as the most complex and difficult hero. He is unique as he possesses a total of 14 spells in his arsenal; 3 of them Quas, Wex, and Exort are reagents and 1 is his special Ultimate Invoke, these 3 spells can have 3 instances, which served as the basic ingredients or components for him to create a spell using his ultimate. Once the reagents or elements are combined, he can invoke one out of ten different spells. His 10 invoked spells are capable of damaging enemies, aiding his allies, and saving himself from danger. His 3 reagents can be upgraded up to level 7 which determines the power and potency of his spells, making it more powerful than an ordinary spell. Because of this, he can be played in almost any role possible. Invoker can be a Carry, Semi-Carry, Support, Ganker, Jungler, Pusher, Initiator or even Tank (though the gold investment makes this highly unrecommended). He is also the only hero who doesn't have Attribute Bonuses; thus, he has average Stats, but his 3 reagents also provide additional Stats to make up for his naturally average Stats. The Invoker, though powerful on his own, is item-dependent; his top priorities are Health for his survivability, Mana for him to utilize more of his spells, and Damage if you want him to be a strong Carry. Because of this, newer players will have a hard time using Invoker, but once learned and mastered, the Invoker will rise to its full potential and playing this archmage is truly a great reward. Invoker is recommended for advanced players.

Gameplay
The Invoker is the most well-rounded spellcasting hero, due to his massive array of spells. Using his three elemental reagents and his Invoke ability, the Invoker can utilize a total of 10 different spells. Due to his complexity and fragility, the Invoker is a bad choice for newer players. With some experience, however, he becomes a force to be reckoned with. The Invoker is capable of massive area of effect damage, powerful disabling spells, very strong summons, and potent enchantments. While other spellcasters tend to be focused in one area, the Invoker has the ability to change his role at will. His spells tend to start out weaker than comparable abilities, but since his reagents have 7 levels each his potential spell power is very high. Although mastering his spells takes perhaps the most practice of any hero, he is definitely worth the time.

At level 25, Invoker has 7 points each towards Quas, Wex, and Exort, and 4 points towards Invoke. Uniquely among heroes, Invoker does not possess the Attribute Bonus ability (i.e., he cannot put points towards "Stats"). Instead, he gains a permanent attribute bonus to one of his stats each time he levels up Quas, Wex, or Exort.

Trivia

 * In the earliest version of Invoker, the order of instances mattered when Invoke was cast. Invoker had access to 27 spells, including the 10 still in game.
 * The name "Carl", in Dota 2 Invoker's responses refers to a "leaked" changelog of DotA 6.72, in which "Kael", Invoker's original name, was mistakenly translated as "Carl"..
 * His fun name in original Dota is Kal-el, an allusion to Superman.
 * His original name is Kael, possibly based on the WarCraft Blood Elf Mage character, Kael'thas Sunstrider.