Nyx by a mile
Slarder is really bad in the meta right now with silver edge falling away Slar really needs too much str items and attack speed items and damage items and by the time he gets those the enemy pos 1 is online too and kills slardar anyway so Slardar bad atm
Nyx has always been amazing because of his ability to create space as a 4 not to mention the map control gained with a good Nyx forcing the enemy ward locations and then easily dewarding. Plus the utility of the burst on Nyx is very underrated. Burst in dota is under rated anyway and having nyx that can quickly smack a Necro for half his health or just straight up kill abaddon outside of his ult range and be able to fight pretty much any other support 1v1 and his aoe stun he is just gg all around