Hard Target brings in a "new" type of spirit with the loa and then divides the aspects of them into two subclasses; Rada and Petro. Sadly the book does not include an explanation about what this means other than which tradition can summon what.
Is there a difference between the two? If yes, then what is it?
What is the difference between Ogoun summoned as Rada and then summoned as Petro?
HT p.126
"One thing to clarify: There are technically no “good” and “evil” loa; it’s more “cool-tempered” and “hot-tempered.”
Rada is the "cool tempered" while Petro is the "hot tempered"
but as Darwin says
"Fundamentally I agree with you. But there are those like Krabinay who perform virtually no useful services for metahumanity"
The Rada side of Ogoun is the defender who will fight for his people. Petro side is that of the killer.
The Rada side of Shango is fighting out of love. Petro is fighting out of rage.
The Rada side of Erzulie is the eternal innocent in love and romance, while the Petro side is that of Jealousy and seduction.
The difference is what personality will you bring with the loa. The Rada, or the Petro.
Santeria character can summon Legba into themselves and play either the benevolent leader or the Doomsayer, though they ideally would choose the benevolent leader as that most matches the saint aspect.