Sub-Terra is all about Insane power, but is easily counterable. Ventus is hardest to master, you need focus and control. Aquos makes your oppenents drown in the abilities of a gate or ability card. Pyrus is about gaining power when you need it, but is so easily countered that don't waste time using it. Darkus takes away your oppenents power, and has a lot of sinister effects. And finally, Haos is about getting big boosts.