There is a difference between wanting a card and needing it and most of the time, we don't need it, we truly want it
Although the board presence gained from using her -3 ability is strong, sometimes it wont hit a relevant creature and leave itself open for attack
This binder has 20 pages and can hold up to 360 cards with or without sleeves
And he wants you to run stuff that's multicolored for more triggers
Even if Kaito's triggered ability triggers more than once in the same turn (perhaps because one or more attackers had first strike, multiple players were dealt combat damage by your creatures, or there were multiple combats), and you return an attacking creature to hand each time, you won't be able to activate Kaito's loyalty abilities more than twice that turn
That -X can devastate most opponents by wiping out their colored cards, which is likely to be most of them