If The Lord of Elemental wasn't enough "strategy RPG prequel coming out May 27 in Japan" excitement for you, your prayers have been answered -- also hitting PSP shelves that day is Blaze Union, a brand new Sting-developed tactical RPG that, story-wise, is a prequel to GBA and PSP hit Yggdra Union.
Set in the Bronquian Empire before Yggdra came along and unified it for herself, Blaze Union's story is centered around the Blaze Knight Corps, a rogue army fighting against the land's corrupt emperor. You control Garlot, leader of the corps, on a series of campaigns against the evil empire, the story branching this way or that depending on your decisions.
Like with Yggdra, Blaze's battles are a mix of strategy-RPG and card action. Before a battle scene begins, you're tasked with selecting which units and "tactical cards" to send out to the field. The subsequent fighting proceeds a bit like a sword-and-sorcery Advance Wars, with you forming multi-unit Unions to beef up your position and using special charged skills to wipe out enemy advances.