I don't think it will damage the esc, but I'd be more worried about damaging the lower C rated lipo. The usual advice is to match the lipos even down to their useage before running them in series.
Lower C rating may mean higher IR in that lipo and more heat from that lipo. If you do this, pay attention to lipo temps and avoid running close to the lvc until you know there's not going to be issues. The testing I've seen on teh HC lipos has showed C ratings may be conservative so there may be even more diff in C ratings than label say.