Manahive

Equivalents to “Kellogg, Dangerous Mind” (a blue card that copies spells/abilities and cares about targets) include:

• “Zada, Hedron Grinder” (red, but closest ability)
• “Naru Meha, Master Wizard” (blue, copies instant or sorcery)
• “Hive Mind” (blue, copies spells for each player)
• “Dual Casting” (red, but lets you copy spells via creature)

Closest blue one is “Naru Meha, Master Wizard”.
Reason: It also cares about copying spells and is mono-blue.