Cold Domination guide in sig for cold powers.
as for Rad, Neutrino Bolt and X-Ray Beam will be your bread and butter for ST until you get Cosmic Burst (some like using the snipe for ST chains but I personally find it too annoying and end intensive). Pick up Irradiate at some point early since it's your best AoE and a great debuff AoE, and if you still want more AoEness Electron Haze works fine but is purely optional. Try to slot Neutrino Bolt with Achille's Heel proc and any damage procs ASAP.
rough guide to power choices:
Solo build
Level 1: Infrigidate -- Empty(A)
Level 1: Neutrino Bolt -- Empty(A)
Level 2: X-Ray Beam -- Empty(A)
Level 4: Irradiate -- Empty(A)
Level 6: Swift -- Empty(A)
Level 8: Travel pool power 1
Level 10: Electron Haze -- Empty(A)
Level 12: Arctic Fog -- Empty(A)
Level 14: Travel pool power 2
Level 16: Health -- Empty(A)
Level 18: Benumb -- Empty(A)
Level 20: Stamina -- Empty(A)
Level 22: Aim -- Empty(A)
Level 24: OPEN SLOT
Level 26: Sleet -- Empty(A)
Level 28: Cosmic Burst -- Empty(A)
Level 30: OPEN SLOT
Level 32: Heat Loss -- Empty(A)
Level 35: Neutron Bomb -- Empty(A)
Level 38: [Empty]
Level 41: [Empty]
Level 44: [Empty]
Level 47: [Empty]
Level 49: [Empty]
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Team build
Level 1: Infrigidate -- Empty(A)
Level 1: Neutrino Bolt -- Empty(A)
Level 2: X-Ray Beam -- Empty(A)
Level 4: Ice Shield -- Empty(A)
Level 6: Glacial Shield -- Empty(A)
Level 8: Irradiate -- Empty(A)
Level 10: Swift -- Empty(A)
Level 12: Travel pool power 1
Level 14: Travel pool power 2
Level 16: Health -- Empty(A)
Level 18: Arctic Fog -- Empty(A)
Level 20: Stamina -- Empty(A)
Level 22: Benumb -- Empty(A)
Level 24: OPEN SLOT
Level 26: Sleet -- Empty(A)
Level 28: Cosmic Burst -- Empty(A)
Level 30: OPEN SLOT
Level 32: Heat Loss -- Empty(A)
Level 35: Neutron Bomb -- Empty(A)
Level 38: [Empty]
Level 41: [Empty]
Level 44: [Empty]
Level 47: [Empty]
Level 49: [Empty]
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I just made a new Defender. I don't usually play defenders so I don't know which powers to get. Can someone give me a build or some kind of pointers? Be very appreciated.