Araumi creates tokens of that particular creature not the entire card itself. So encoring Gary will create tokens that aren't cards and only copy Gary not the entire card. So for example if Araumi is the only permanent you have on the field and activate Araumi with Gary in your graveyard. Having 3 oppponents you exile 3 cards and pay 5 mana to cast Gary. The Gary Tokens enter which now they are colorless. All 3 Gary Tokens trigger which only see Araumi has 1 black mana granting you 3 life lost for each opponent and gaining 9. The (3)(B)(B) is the casting cost but isn't Gary the creature itself. So by encoring Gary you won't get your opponents for a life lose 21 while gaining 63. Again pay 1 more mana for Kokusho, the Evening Star instead.
Unless I'm missing something weird about the encore mechanic, this is wrong. The reminder text on Araumi says that it creates a "token copy" of the creature. A copy copies all copiable characteristics of the target, including CMC and color. So, each of the Gary tokens would be black and have a CMC of 3BB. Which means that, upon entering, each of the tokens would see a devotion to black of seven, assuming Araumi is the only other card with a black pip. So, there would be three triggers for seven.
The relevant rules are:
706.2. When copying an object, the copy acquires the copiable values of the original object’s characteristics and, for an object on the stack, choices made when casting or activating it (mode, targets, the value of X, whether it was kicked, how it will affect multiple targets, and so on). The copiable values are the values derived from the text printed on the object (that text being name, mana cost, color indicator, card type, subtype, supertype, rules text, power, toughness, and/or loyalty), as modified by other copy effects, by its face-down status, and by “as . . . enters the battlefield” and “as . . . is turned face up” abilities that set power and toughness (and may also set additional characteristics). Other effects (including type-changing and text-changing effects), status, and counters are not copied.
706.2a A copy acquires the color of the object it’s copying because that value is derived from its mana cost or color indicator. A copy acquires the abilities of the object it’s copying because those values are derived from its rules text. A copy doesn’t wind up with two values of each ability (that is, it doesn’t copy the object’s abilities and its rules text, then have that rules text define a new set of abilities).