Veno, the Mysterious Merchant
Veno is a stranger who has recently moved into Haven. Compared to other Strangers in Haven, he has no visible eyes as they are covered. He speaks in a slightly deeper voice too. Oddly enough, no snipes appear around him which is quite strange for a stranger.
He has very rare equipment and other things for sale but will only trade them if the Knight has gained enough of a reputation to purchase said items. Items can range from rare Handguns that are akin to Winmillion and a Sword of the Stars. (Hinthint)
Reputation would be earned through various means unlike directly purchasing the items, the player must complete a series of tasks to improve their reputation. Veno offers 3 Daily Quests and 1 Weekly Quest. These are much like Prestige but work slightly different than expected.
For example, one of the Daily Quests would be "I'm looking for a crystal from a Silver Trojan. If you would obtain one for me, I would be more than thankful."
This is just an example, a Silver Trojan would appear in place of any Trojan within the Arcade on non-boss depths. It has a 25% chance of spawning in any given place of a normal Trojan and is slightly stronger, faster, and larger.
Completing said mission would give you some reputation (Example would be +15) thus improving your rank within his store. The more reputation you have; the more you unlock! Other quests would involve something much like "Complete Royal Jelly Palace with a four-knight expedition using only Cautery Sword." and things akin to that.
Onto reputation and purchasing in-depth: Reputation as stated earlier is a point system within his shop. Reputation would increase the amount of equipment you may purchase from within his store. This goes by a "rank" system. For Example:
Your Knight starts out at Rank 1. To upgrade your reputation you must earn 600 reputation in order to reach Rank 2; granting you much more purchasing options and benefits.
But let's continue onto a currently running event: Black Kats. What does this have to do with Veno you may ask? To make the mission less of a grind-fest (or even an option) how about giving Veno a specialized quest that works the same way but the quests give you a unique token which can be used to purchase some material-specific things or even an incomplete Book of Dark Rituals?
There's quite a bit that has been said here and I'm hoping this is well-received.
could reputation be based on rank perhaps (as in there are rank separated reputation levels)? because a low gear player could just rack up reputation and just get a higher weapon then they should
and possibly instead of special missions u need a special material from a semi-rare enemy like you said, maybe put it only in arcade so people need that for reputation, arcade really needs something special aside from basil