When Kaho enters, search your library for up to three instant cards, exile them, then shuffle.
{X}, {T}: You may cast a spell with mana value X from among cards exiled with Kaho without paying its mana cost.
Kaho's activated ability refers only to cards exiled by its triggered ability. If another effect exiled the cards, you won't be able to use Kaho to cast those cards.
1 Jun 2005
If an effect takes a card Kaho exiled out of the exile zone, then you can't use Kaho's ability to cast that card.
1 Jun 2005
If another player gains control of Kaho, that player may cast any of the cards exiled with Kaho's ability.