There's objectives in Doom Bots?
Does that mean jungle monsters + Teemo?
Doombots is on live?!
I get the picture, I tried something similar with Cho'gath.
Partially because I preferred Runic Echo for mana sustain over RoA, rings or morrello's. (Uncertain how much I could rely on kill or farm). And since Smite was a go to summoner in this mode anyways.
On a similar note, if your particularly mana hungry, try and secure Blue buff when possible. Particularly early so that you can keep up the wave clear.