Eiro pushed his hand forward, conjuring a compressed stream of the hottest flames he could bring forth. Everything around Merlin was being singed, except this old man himself.
Merlin waved his hand around and once more created a mass of arcane magic. He didn't seem to have a wand on him, so Eiro was at a light advantage, at least. The arcane magic was still able to fend off Eiro quite a bit, however. Now, instead of turning into something like ropes to hold him down, the arcane magic turned into a bubble that surrounded the Demon, entrapping him.
Slowly but surely, the bubble was shrinking, "It is a shame that it came to this, Eiro. I will express my condolences to your children soon, do not worry."