Not sure if I’m just using him wrong but he’s kind of a let down in my opinion

ive maxed styx and it barely makes any difference 

the multiple spell slots are cool but he just doesn’t stand out as special or useful

anyone else feel the same? If not, what are some tips to use him? 

He is all around hero. The down side that it has is his Scylla as own spell which weakest in game. Units that have physical as weakness are only scratched by Scylla.

At the moment Achilles is the worst hero after ascension 40 and above.

Achilles not Hercules ?

What lvl do you have him at? What gear? Maybe he scales better than he starts. He should have a lot of leadership points. Plus I think he has a lot of resistance. He might even get a bonus perk like Ariadne who naturally has a very high chance to petrify (without gear). I wouldn’t mind seeing his stats.