Even if some or all of those creatures are no longer attacking or no longer have power 4 or greater when the ability resolves, they still count towards how many lands you can search for
If you want to build Katara, I'd highly recommend Tetsuko Umezawa, FugitiveTetsuko Umezawa, Fugitive
Instead of killing the card which just lets them recast it you trap it on the field as a useless bug
Despite being a bad card, it was memorable for being a part of the original Alpha set, which automatically gives it some degree of iconic status
Its also a fast-beating creature thats easy on the mana and can dole out some damage before shields are fully raised
Whatever he needs, whether it be money, connections, or power, he takes as he likes and will do anything to stay on top