First-ever deck I've completed when I got introduced to Weiss Schwarz. It may be old, but for as long as it's Kanade, it'll work out as this deck work on me with wonders.
LV0 = Keep "Student Council President, Kanade" to search for L1/1 "'Messenger of God' Angel" ready for LV1. If ever you both have "Battle Meeting, Kanade" and "Kanade's Innocent Eyes on hand, its attack power can be increase up to 4.5k for one turn. Then, play as is as you try to accumulate stocks for the next turns. Avoid losing too much of your L0s, if you can.
LV1 = Keep "Normal Girl, Kanade" ready for L2. When CX/s got clunk on your stock, you can always use pay cost effects such as "End of the Confrontation, Kanade" and "Kanade & Otonashi", or paying the cost for "'Messenger of God' Angel". You may use the other "Student Council President, Kanade" ability for the cards you currently need. At the same time, it compresses your deck for a slight chance in cancelling soul damages.
LV2 = Play offensively. If you got the changer and you can use it, the better. Use "Worrying Kanade" as support. If you have "Kanade Sending Everyone Off" on your stage, it'll compliment "Kanade Standing Still" due to its ability. Use the CX Combo's, "Awkward Confrontation, Kanade", when you're into a situation, where you either wanna bounce a character that you can't deal with or you're going for the soul damage. And for "Kanade Waking Up", you can use her as your powerhouse card.
LV3 = When you successfully manage to do L2 changer ability and didn't get reversed or targeted, you have a chance to win the game. "Parting Words, Kanade" can clunk your opponent's stock when there are CX/s in it. Don't worry about giving them the free stock for as long as you can clunk at least one CX in their stock when their deck refreshes, it's worth it. "Kanade Tachibana" can be use when you can pull for the L2 changer again for the L3 heal effect. Otherwise, you can use the ability to go for the win. Lastly, "Kanade Under the Blue Skies" is a situational card, where you think you lack the soul damage. You may use its ability to do more soul damage. Though, its "-1 soul damage" ability is quite the double-edged sword as your opponent might use it as an advantage regarding soul calculation damage.