He really does have great synergy with Shuri, yeah. For a few matches, I saved up about 12 black and enough red to for Shuri to fire her power at least once. First I'd fire Shuri's red as many times as I could, then start firing MODOK's black until I had enough red for Shuri to put down more fortified tiles, and continue. With any luck, I'd collect a few more black AP from line clears to keep things going longer.
All the while, the cascades cause massive damage due to the passive portion of Shuri's red. The bug that treats all tiles destroyed by a line clear as matched is a massive buff for Shuri.