She summons a random neutral creature from your hand. For example, if you have Bahamut, Lucy, Gilgamesh, and Saha in your hand, each has an equal chance of entering the battle.
Added 2 minutes later
Although... Rereading the description, it seems the opponent had no one else besides the second Saha. And I haven't played with this card myself, as I haven't gotten it.
Yeah... If it were random, the card wouldn't be very valuable.
Either he was mistaken, thinking that the second Saha could also bring someone out, but of course, it didn't work. Yes.
Master Tier discussion

No, not random. And no, players at Master Tier aren't that clueless, Ment.