There will eventually be four playable characters but as of Episode 2 there are only two available. You start of as Rose and eventually you will be able to play the gun toting bounty hunter known as Wolf which as of yet not much is known. Rose however is shown to have a close relationship with her friend Xan which is eventually revealed to be romantic.
On certain missions you will be able to use Rose and Wolf on the same grid where being successful will mean taking advantage of each character's strengths. Rose is a melee character who is best when she is close to her enemies while Wolf is a ranged character who is most effective from the outskirts using his gun to pick off the enemies that Rose damages. Eye squares will increase the attack range of Wolf's gun and he has several powers that inflict status ailments such as poison and stun.