at the chaos mage suggestion:
I consider it kinda weak...
Just bear this in mind:
death coil deals 1000 damage at lev 6
your skill deals 1-1200 damage at lev 6
so basically, your skill has a 20% chance of dealing more damage than a death coil while on the other side, there is the possibility of it not even scratching the hit point regeneration rate of a hero.
if you wanna create something random, rather make it 750-1200 at lev 6 or sth like that yet I kinda feel, so much random stuff will lead to frustration rather than really make some1 having fun playing frenzy.
"Wtf, mah roulette always hits that gay ass ava on full hp!"
"Wtf? Your fukken roulette killed mah hero liek 5 times in a row, fukken lukker!!!!"
"Wtf? mah chaos bolt didn't even scratch teh 100 damage mark at liek 10 subsequent lev 6 casts!!!"
"Wtf? I just died? 2 casts above 1150 in a row? omfg"
and so on

your skill is just too much random. as for your ultimate, it's kind of a global cattle ulti which is best placed when there is some clash at mid and all heroes are low hp from that starfall which didn't get cancelled in time etc.
But just remember: there are at least 12 heroes on the map.4 to 5 of them will have hitpoints where your ult will be waste, like 5 more will not die from the ult directly yet will be forced to tp and only 2 other guys might eventually die from it, even worse, if it's some farmer in some remote base who just drops to 1 hp by your ult, raking in a ton of cash for that team rather than for you.