There was already such a thread, wasn't there?
Might have been a round in the FT Tournament i don't know.
Anyway, here's what i think:
Round 1: Laxus wins like high diff. TO Sherria was impressive because she actually defeated Dimaria, but her spells themselves, or how she moved, wasn't that impressive. I still rate Laxus about TO Sherria, and so far nothing said about it changed my mind.
Laxus is deadly, and there's no doubt in my eyes that he's be able to deflect Chronos's laser beams (since TO Sherria could, and since DF Wendy was abe to see them coming). How he reacted to Wahl's bullets makes it clear that he has a pretty good reaction speed.
2 factors make it a high diff imo:
1) Age Scratch. Laxus will endure A LOT of pain. However that's just pain, not significant damage. Laxus proved that he was able to withstand pain with his iron-like willpower. Also that's assuming Laxus would just let her cast the spell without attacking her (i do believe that he could overwhelm her, as he was overwhelming Hades back then)
2) The fact that Dimaria (Chronos) was unfazed against non-God Slaying Magic attacks. Laxus packs way more fire power than DF Wendy, but still Chronos has proven to be tanky (aside from when facing GS magic).
Round 2: Dimaria wins in a split second.
We could argue that Laxus has a higher magical power compared to END, but... That's just an assumption. Would Laxus be able to resist Age Seal? There's no evidence, hence i won't assume that he would.