frisk cans still be in the timeline if u dont realise after the fight papyrus vs the blobs  sans comes up from the elevator and says to papyrus and sayes where is the kid  payrus siad chara then he siad the another kid meaning frisk  sans was filled with determation from udyne and chara and frisk as u remeber gaster wanted blood samplies  of all determation users  plus how the hell did chara break the heart lockect if chara replaced frisk then who would of replaced charas