Kyogre DOES NOT in any way, shape or form get killed by Groundon in one Solar Beam, It takes at least 2 because:
Kyogre Base Sp.Defense = 140
Groundon Base Sp.Att = 100
See the difference, Kyogres defense is higher than Groundons attack and as there is no STAB there is no way there will be a OHKO, this is why Kyogre can OHKO Groudon with Surf because
Groudon Base Sp.Defense = 90
Kyogre Base Sp.Att = 150
Once again look at the difference, Kyogres attack is greater than Groundons defense, plus STAB giving it a 10% boost making it 165, it makes a BIG difference
Once again, Kyogre wins