Ive enjoyed using Triforce, but I don't see him as a DPS'er, as I've explained. The rylai's is generally built early anyhow, the order of items isnt set. Sometimes I've felt that the slow isnt as important as the Manamune for example.
Ive generally ended with a high amount of assists and a couple of pickup kills, I reckon if you wanted to do more damage the Triforce could easily replace another item. Thanks for the input anyway :)

I'm curious why you don't have Trinity Force in this build since it increases Skarner's damage output so greatly (especially with how much he spams his Q ( Shattered Earth). You seem to have the mana to support spamming in this build (with Manamune) but the item that takes advantage of spell spamming the most is missing.

I also might suggest switching the Gunblade and the Rylai's in your build if the main goal of the Rylai's is to turn Skarner's E ( Ixtal's Impact) into a slow. The Gunblade is more expensive but its active is a targeted 50% slow as opposed to the skillshot 15% slow with Rylai's and Ixtal's Impact. With a Gunblade you trade some health for a lot of Spell Vamp and Lifesteal which, while not quite the same as survivability, does give you good sustainability during and after a fight.

Mad guide bro! might try it out later todays!