We consider the case where dark matter is accompanied by an almost mass-degenerate colored particle. The colored particle is typically long-lived and can, in pair, form a QCD bound state which have interesting implications on cosmology and LHC physics. Bound state formation enhances the effective annihilation cross section significantly. For the stop-bino coannihilation scenario, we find that the bino dark matter mass can be as heavy as 2.5 TeV. Meanwhile, at the LHC, a 750 GeV quarkonium can accommodate the recently observed diphoton excesses. We show with explicit model building that other LHC excesses may be accommodated simultaneously in this framework.