For over half of his solo series ( and his back ups in Warlord) he was not much over street level. In fact he became a master swordsman and H2H combatant because he was so often without any power.
He has maybe 4 or 5 feats that are even close to herald level and ALL of these are either amped by outside force, MEGGARLY prepped for, or he literally gave it EVERYTHING he had in a single attack and was then completely powerless for 3 to 5 issues ( having used up every bit of energy his star gem could hold).
early issues of Arion have him fighting an enemy of Atlantis who use aircraft. He beats some of these and helps drives others back.
He then falls to his brother who made him use too much energy in an assault and chains him in a cave away from light ( light being the source of his power stored in the red gem on his chest). He tries to free himslef from the chains ( which are made from a metal immune to magic) draining his last vestages. Courtesy of his father ( an Atlantian god) moving a star closer too him he is repowered to a level he had never had before. he then reaches out and absorbs more light from every star in the heavens ( one of the 5 feats) and defeats his brother, but at the cost of his fathers life.
A couple of issues later he comes across a citadel where an entity is absorbing all the energy of the sun ( cause of the current Ice Age). He destroys that entity but uses again every bit of energy he had to do so.
For the next few issues he is completely powerless on a quest to find a new source of magic. All he has is a sixth sense and very very mild TP ( part of his learnings). BY the fourth or 5th issue after that he finally had enough energy to be able to create minor illusions.
At this point he get's back to his father palace in Atlantis and get's some candles ( or sticks ) that each contain a part of his fathers essence. He can use these to draw on a little of his fathers magic but only one spell at a a time. uses these IIRC to defeat his brother again.
Another quest this time takes him into the bowels of he earth and the darkworld to find his fathers magic citadel and source of it's power. he brings the citadel back to Atlantis where again his brother is ruling and again uses ALL it's power to defeat him ( high end feat 3).
Then another quest this time into his fathers books ( buries himself in his fathers castle and library). Eventually calling on the weaver to tie magic to his soul again.
he looses the power once more right in time to face his mother Dark majestra. The weaver owing a debt to a goddess who apposes Majestra again links magic to Arion who while he is in his mothers dimension ( and has a hereditary link to it's power) uses it to defeat her ( high end feat 4).
Standard powers are blasts, force fields, flight, intangibility, illusions, mild TP ( these last two he uses when depowered for that other half of the series) and control of elements ( wind earth etc). In one of the last issues of his title he senses a threat that he says " has power to match his own" which turns out to be a space ship.
The other high end feat is when he faced a chaos god while another god of light near by unknown to him was feeding him power.
here he fights a minion of a dimensional entity a fraction the power of the likes of Mephisto ( who Warlock has defeated) and not only can't he harm him is easliy taken out
for around 60 to 70% of his published stories all Arion can do is create illusions and sense danger. he fights more with a sword than he does with magic and uses hand to hand almost as much as magic. The only way he can match Warlocks average level feats is to commit every ounce of energy he has on some gamble that if it fails he has no power left to do anything and you don't think it's a large difference.
what would you call a big difference. cause from my standpoint the gaps about as big as Superman to Luke Cage
what recent portrayal. AFAIK he hasnt been in print since the early 90's. Warlord, his solo run, Immortal Arion mini( mostly crap - a bit contrary to anything else) tales of PG post COIE early where he did nothing, and a few early post Crisi action issues and WW ( in which he was possessed and controlled like a pupet by morgan Le Fey and powered by her)