Best animation software

Can any one tell me which 2d animation software is best for linux . Plz don’t tell me synfig…if synfig is your answer then solve my this problem… i faced one problem in this that the downloaded catoon character , which i download from freepik website …when i open image in synfig , i am not able to divide other characters from same image as you also know that free catoon character contain three or more character in image …so, i am not able to animate one character separately .