Hey I beat him today as a Siren it was very close, but I used the Baby Maker to start the fight and did as much damage as I could before he summoned his bots, at which point I circled around him while using the phaselock to draw everybody together (skill tree converge) and shot rockets (decent rocket laucher Terramorphous dropped) and threw corrosive grenades to slowly chip away at the bots. Then leaving one last bot alive started using Baby Maker again when his shield was down. This worked up until he jumped and put me into last stand, but he had low enough health to just keep throwing Baby Makers at him which finished the job. Far from a perfect victory but as a fellow solo Siren hope it kinda helps. All I know is after trying Master Gee I'm done with these super boss battles too stressful.