Pantheon the worst assassin?

I main pantheon so i think i have a enough knowledge on the issue. Though i would like to hear others people views on this. To me the idea of an assassin is to kill a high value champ. Most assassins in the game have a feel an elusive feel to them. Both playing as and fighting against in the game. For example Shaco Talon and Twitch can go invisible. Other assassins have an escapes or a form of evasion ability. Pantheon has his stun with his W but that only helps if there is a jungle monster or minion near by for an escape. If he can ward hop like Lee or Jax that would be descent. Granted i have stun other champs and got away but its rare that i made it out alive. Now his ult isn't that great of an escape seeing you're standing still waiting to jump that can be stop by another champ. Now i know his ult and stun aren't meant for escapes but the fact he is labeled an assassin without any good form of evasion seems wrong.He has great pros don't get me wrong fighting him can be really hard. Though his abilities and design are more for a tank its feels. He is based after Spartans and they were tough guys to kill. He cant really 1v1 a Garen Jax or Daruis at 6. I know he is a early to mid game champ but it doesn't feel right with him. Spartans were killers both as a group and alone. Pantheon team fights are really good early to mid game. Though he lacks in 1v1 with certain champs and i don't think he should. Also if i had to redesign him it wouldn't be that much of a difference. HIs passive is the same but 3 hit not 4. Q stays the same. W is a skill shot like Tristana but if he lands in the center of the skill shot it stuns them for 1 (1.5 max) second. The outer part can have a slow for movement and his passive can stack twice. His E and ult are okay but i wouldn't want him OP.What do you guys think i would like to know.