So this is my Wtf Heim. I have done quite a bit of testing with this and start off with a Philosifer's Stone, then move on to the rest of my equips, re-placing the phil stone with a zhon ring if the game extends that far(or you can use an annoying/survivor equip insted of zhon).
I feel like a player really needs to know his run speed and ability cooldown in order for them to run 3 enemies that are charging at you. I tend to try and keep the cooldown buff handy and ghost ready to be casted while waiting with 2 turrets in the bushes and lure enemies at me. If you have grenade maxed early with at least 1 point in Upgrade then you can handle 2-3 champs as long as their not tanks, if anything take out just the squishy and retreat. Notice that the grenade stuns, rylar's scepter slows with skill atks and the frozen mallet slows with normal attacks, this gives you a HUGE advantage on single and dbl enemy encounters.
This heimer build is especially good do to the high armor and decent magic resist as well as being complemented by the 2.9k hp.
Well, this is the build ive been loving for the past few days now and hasn't failed me yet. Hope you enjoy it!