The Obsidian received 5 buffs in balance patch : AOE, shield regen boost, shield / health rearrangement, charge muzzle delay reduction, half energy consumption for its shield. It then appeared that it was no longer the Obsidian, but the OPsidian. Hence we removed buffs it received until we find good balance. It is not nerfed at all, it still uses 2 buffs in the list (charge muzzle delay reduction and shield / health rearrangement) compared to before. The only real problem the Obsidian had before was missing / shooting at an already dead target. Now that it wastes much less shots, it's a really strong unit.
The blaze also received significant buffs and the mobile shield consumes a lot less energy than before. Overall, Aeon t2 land is much better, and the goal is to make Aeon T2 competitive, not OP.