
The Toussaint Knight Steel Sword is the best craftable steel sword, and it is level.
It is possible to "steal" meteorite pieces from blacksmith by simply dropping (selling is also possible) them during transaction, and later re-use them to another sword. If you have Blood and Wine, the best Steel Swords are available from that. If you cannot get G'valchir, Meteorite swords that cause bleeding (three red or three yellow) are probably your best option when fighting Greater Brothers and especially Mutant assassins towards the end of the game, as they are immune to most or all other effects found on non-silver swords. If you want to collect meteorite swords, simply store your primary sword at an inn prior to the transaction with the blacksmith. Any existing primary sword in Geralt's inventory is dropped, and disappears as soon as you leave the shop. You cannot use ore to upgrade the stats of an existing sword - it always takes three pieces of ore for this transaction, and a new sword is created.
A newly forged meteorite sword will fit in Geralt's primary steel sword slot or the heavy weapon slot, see inventory.
Unlike branding rune swords, forging a meteorite sword does not require a steel sword to start with only three pieces of ore are needed.