All battle cards in Megaman Starforce 1 and 2, like the battle chips from the Battle Network series, are organized into three categories: Standard Class, Mega Class, and Giga Class. Of these, Giga Class battle cards are the most powerful and rare in the game. A player can normally equip only one Giga-card in his folder at a time, and the Giga-cards can only be found near the very end of the game. Unfortunately, despite their rarity and overall power, the Giga Class cards in the two Starforce games have been disappointing so far. While they have power, they just are not very visually impressive or cool enough to match all of the hype built into the concept of the Giga-class cards.
A big part of the problem is that many of the Giga-cards in the Starforce games are based on the attacks of the various bosses from across the game. The problem is that all of the more than 40 Mega-class cards are exclusively based on boss enemies too. For example, Taurus Fire has a set of three Mega-cards named after him that execute a spreading fire attack that does various amounts of damage, ranging from 100 to over 200 points, based on the specific Mega-card. However, there is also a Giga-card called Ox Tackle in both Starforce games that is also based on Taurus Fire. This card executes a linear charging attack that does around 500 points of attack. This just seems weird though, since both of these attacks are fairly basic attacks used by the same boss. If anything, Taurus Fire's spreading fire attack feels a lot more like his ultimate attack, particularly since there is nothing flashy or impressive about watching Taurus Fire shoulder charge an opponent.
In comparison, almost none of the Megaman Battle Network Giga-chips were based on regular bosses. Instead, Giga-chips were based on the most powerful and distinctive enemies in the series: the optional super-bosses Bass and Serenade, the various final bosses, and Megaman's powerful rivals Protoman and Colonel. So while a Giga-card would be historically appropriate for a character like Rogue (who both channels a lot of Bass and Protoman's style and is the most powerful enemy in Starforce 2), it makes a lot less sense for a minor throwaway villain character like Blizzard Yeti to be associated with a Giga-card.
Another problem is that the list of Starforce Giga-cards contains a lot of really bland choices such as Aqua +50, a battle card that increases the power of another Aqua element card by 50 points. While this card can be very useful in certain situations, it completely lacks any kind of style. There were support type battle cards in the Battle Network series, but those were cards like Folder Back, which had the unique effect of restocking the player's folder (allowing the player to repeatedly use powerful combos), and Hub.bat, which was not only based on a long-standing plot element from the series but also completely supercharged the user's stats.
A problem particular to Starforce 2 is the lack of a version-themed Battle-card. Ever since Battle Network 4, the player has usually received a Giga-chip/card that was based on the particular version of the game as part of the plot. For example, a player going through Megaman Starforce 1 version Leo will receive a Leo Kingdom GX Giga-card as part of the plot. I have always liked this tradition, since these Giga-chips have often been the coolest and most thematically appropriate Giga-chips of them all. In Starforce 2 though, the player gets a bland boss-themed Battle card in place of one of these.
Here are a few ideas on how to improve the Giga-card selection in future Starforce games:
1) Drop the boss-themed Giga Class cards. Rogue gets an exception.
2) Make the three Admin cards from Starforce 1 recurring. They were cool cards that are based on characters that are still out there somewhere.
3) Create more Giga cards that work off of the themes of the various games: constellations in SF1 and ancient civilization in SF2.
4) Make the cards based on the Final boss into normally available Giga-cards instead of rare tournament prizes that regular players never get to see. Version specific Le Mu cards that used Le Mu's vulcan, sword, or drill arm attacks would have been very cool.
5) Create interesting and flashy cards like the Phoenix/Death Phoenix pair from Battle Network 6.
Getting Giga Class chips or cards often takes putting in hours of work in a game's post-game section. The end reward should not disappoint. So every Giga card should be cool and exciting.