Magian Main hand weaponFollow

Depending on the rest of your current gear/merits, I'd suggest either the STR/Attack Kila +2 or the DEX/ACC one.

If you are looking for the most power, Kila+2 Str/atk version is the highest general damage dagger you have available via magian (excluding relic/mythic/empy). Do not underestimate the power of atk! Alternatively the Daka+2 is still excellent DPS, huge damage and gives access to Rudra's Storm at the expense of some speed.

The eva kila is very powerful if you tank regularly. 25 evasion full timed in a weapon slot is massive, and your not giving up much of anything for it. It is still a solid dagger (D43/del201).

Really, just about all the magian daggers are excellent. Kila(str/dex/agi), fusettos, Parazoniums(1-2, 1-4, DA10%) are all suberb weapons. You can really mix and match any 2 of them and you will be fine as long as you stick to the general rules. If acc is low, a dex/acc dagger is better. If acc is capped, dex dagger sucks. If you need eva, put on agi kila. If you just want to kill things put on str dagger.

If you have to do ONLY one, i would do either the str dagger (general DD), or the Eva kila (if you tank a TON). Depends on what you find yourself doing as thf. I would heartily recommend doing both. They make a nice combo and still nice to swap when you get a 3rd dagger to deal with based on tanking or DDing.