How much does anyone want to bet that even after he spends it against Oceanus, it's still going to have quite a few side-effects on him?
It would not surprise me, at all, if Helios just gave Kon a titanic equivalent of Divine Awakening. Because gods can do it (at least chinese ones), so why not titans? Either as a side-effect / safety feature (so Kon can survive being filled full of Sun's power) or just because he could (and because
Infernal Primordial Exalted are awesome; and because that way Kon is even more like Diana).
Actually, no. They had notice, so there were very few ships in the area and they got evacuated. The death toll wasn't all that great. In trying to show that there are things the heroes can't handle, the Light are showing exactly how on top of things they are.
Speaking of, the consequences, from different perspectives, are going to be a lot of "fun" for everyone:
1) To anyone who doesn't have intimate knowledge of kryptonian biology at the very least, and kryptonian-human-genomorph hybrid biology at best, and also both mystic senses and knowledge of Kon's personal relationship with Helios, ie pretty much everyone not on the Team and outside Themiscyra, it would look like Kryptonians thrown into the sun can super-charge to gigaton level if not beyond (on the assumption that Kal-El would have been stronger, since he's fully kryptonian). Ie Superman's threat ratings will be revised upwards, a lot. Superman being overestimated could be a fun plot-thread.
2) To religious kryptonians (I'm looking at you, farmer lady who hates house of El), assuming they see it, this could be quite disturbing - a half-kryptonian clone being granted a very obvious blessing by a sun god (assuming even they know it's not Rao, and further assuming Helios wasn't in contact with Rao when they did it)
3) To amazons, the world was just saved by their prince wielding a power of a titan when the gods utterly failed, with only one of them even making an appearance. I strongly suspect Helios will receive a lot more worship in coming days, with likely a state-mandated celebration in his name at the very least. Also maybe Poseidon, if he's still alive at all.
And then there are consequences of whatever happens after Oceanus's avatar is disrupted. Because from what I gather, chances are, his power has to be keyed to someone to prevent his reemergance, and the only people even remotely suitable for the role in the general vicinity are: Diana, a young titan herself (basically, Skyrim Dragonborn situation), Sephtian himself, the mage doing the transference, Koryak of Atlantis's royal bloodline (which should give him some mythic oomph), and Canis, a new god. MAYBE Kaldur, but that's less likely. Any of those receiving a large portion of Oceanus's power (at least as large as Poseidon had) would have story consequences.