Five Chosen Human that by five God that keep the Magic in Gensokyo (and anywhere) in check. Chosen by the Weapons they Wield.Also take a look at my Characters in the The Crossroad them for some more tropes about the five.Tropes for All Five:
The Leader: Paul Miller, Even they are all Leader of they own Summons Creatures, Paul can count as the Team Leader.
The Lancer: Edward McDeviant, Part of being a Best friend and being the one used Black Magic.
The Smart Guy: Max Saibaa, Do to being the Blue Champion of Logic and Technology, and even with that titles he would make Cybernetics that he have one himself.
The Big Girl: Sore Thunder Hikari, From being the one with the Fire (and Other from Elemental) Power of Red Magic, However she can also be the The Chick.
The Chick: Ni Fureya, As she the one give Paul the voice of reason for being the Champions of Magic and tried to be Love Interests for Paul but fail, Like Sore she can also be the The Big Girl by the Big Fatty of Green Creatures that she Summon.
Hero of Another Story: A given that some of they story are not even in Gensokyo, most of they adventures are across other planes of existent. And even in Gensokyo they not well known.
Magic A Is Magic A: Even if Gensokyo's Magic (or any other Magic) isn't the same as Gathering's Magic, All of they Magic and Spell are made of Mana from Lands or the Weapons if need too.
They do have spellcard for the fair battle in Gensokyo, Some of card with the Magic's Colour Themes. Infarct they most taken care of the one, who've illegal disused the spellcard and using they own Power. As the spellcard do not upset the Magic with in Gensokyo.
Wrong Context Magic: Because in away, they Magic don't follow the Bullithell's Spellcard ruled, But they do follow it.