After some experimentation, I've come up a descent item and skill build for this hero as well as situational combo. I could kill almost anyone on 1on1 (except centaur or any tank heroes late game). I could even always get double kills or triples (sometimes though sacrificing own life). I can roll even to 5 heroes pushing and manage to get kills even when alone.
1. get grip first (for stunning, saving yourself or an ally if gank)
2. Rolling Boulder
3. Rolling Boulder (at level 3 u can even manage a kill if you have a good ally)
4. Boulder smash (ward of ganks or save ally or kill escaping heroes with little hp left, takes some practice)
5. Rolling boulder (you should manage a kill by now IF you have boots)
6. Magnetize (you can kill virtually anyone at this stage: guts, confidence, careful placement of stones = double kills)
7. Rolling boulder (anyone in your path = GG)
8. Max grip and Magnetize, then stats (Boulder smash is retained at level 1)
1. 2 sets of Tango (6 pcs), 1 Healing Salve, 2 pcs gauntlets of ogre str
3. sobi mask
4. if you can manage a kill go for Power Treads
5. complete URN (this will cover your healing and mana problems)
<<go kill anyone>>
6. Robe of magi (increase mana pool a bit)
7. Chain mail (+armor helps on ganking)
8. Complete blademail
<<probably you wont get godlike but it is highly possible, just rape them>>
9. Sange (+hp and maim is good)
10. Ghost scepter (useful if there are a lot of enemies, helps you place stones strategically without being hit...casters? go BM)
11. Complete Heavens halberd (kinda contradicts your BM but it really is awesome against hard hitting carries without BKB)
<<if the game drags on>>
13. Boots of Travel
14. Ditch Urn ang get Heart of Tarrasque
1. Basic: place stone at the back of enemy hero(es), Grip the stone, then Roll, magnetize, then use URN charge to enemy, use Bladmail if it fights = kill. Escaping enemy heroes? place stone to that hero to extend magnetize..place another one ensuring that it will be hit with you rolling to that enemy, whack and place stones in advance = kill.
Grip - Roll -Magnet -Roll
2. Descent: put stone in front of you then roll to enemy, magnetize, urn, blademail, escaping? stone and grip and roll = deads.
Roll - Magnet - Grip - Roll
3. Difficult: put one stone in front, boulder smash the stone (ensure hitting most heroes), then grip THAT stone, then Roll to THAT stone. lol (it takes practice and it can be done). Watch the stone never to go its full distance on boulder smash, grip as soon as it passes the heroes then roll. Then magnetize, Blademail, stones in advance, with radiance everyone should be laying on the ground. (Silenced + Stunned + Slowed + Damage over Time = GG)
Smash - Grip - Roll - Magnet - Roll (depends)
1. any heroes with stun/slow/trap
1. Centaur warchief (3rd skill hurts against your magnetize)
1. Blinks, silence, Invisible (but can be killed)
1. You don't need crazy mana regen or mana pools since your skills mostly depends on stones to be effective and it takes 25 seconds to restore 1 stone, Rolling boulder at 4 seconds CD can be spammed costing only 50 mana.
2. Force Staff is preferred against Blink dagger (if you ever considering one), because it helps in escaping gank attempts very very well with rolling. You have rolling boulder for initiation so dagger is a waste.
3. For fun games, get treads, urn, dagon 5, shivas guard and HoT. If you can farm these items well then the result is much less the same.
Feel free to correct or comment.