Jarvis, Earth's Mightiest Butler

Cast-trigger card draw is one of the oldest engines in blue, and the design question is always the same: what do you have to cast to turn it on? This one keys off Hero spells, which anchors it to a creature type rather than a color or converted mana cost, so the whole build revolves around loading a deck with Heroes and using this as the payoff that refills your hand as you deploy them. The 1/4 body is the giveaway that draw is the entire job here: this is not a beater, it is a wall with a card-advantage attached, priced to sit back and cash triggers while your Heroes do the fighting. What makes the trigger reliable is that it reads on cast, not on resolution, so it draws even when the Hero spell gets countered or the creature dies in response; the card is banked the moment you put the spell on the stack. That instant-of-cast timing also means it fires off flash Heroes, cheap Heroes chained in a single turn, and anything that lets you cast a Hero from an unusual zone. Advisor as the creature type is a wink at the character rather than a mechanical hook, but the structural idea is clean: a low-power, high-toughness enabler whose value scales entirely with how densely you can pack the qualifying spell type around it.