|Stahl isn't that great, everyone knows it. Which is why he will make FANTASTIC arena bait when put with a terrifying cavalry team. Give him as much bulk as possible and he can be a viable, bulky brave sword user. He might not be the fastest or most powerful, but his defense and health give him enormous bulk against physical attacks. And most people forget when looking at him, he IS a cavalry unit, capable of both giving, and receiving +6/+6 cavalry buffs.
Brave Sword+ will give him quite a bite against reds and greens, while Fury 3 makes his attack stat 42, not bad with a Brave weapon. More importantly, Stahl's defense will reach 37, that's an effective 82 hp against physical damage units, making him very hard to bait and kill. If the enemy player fails to kill Stahl, but damages him, it leaves the opportunity for all sorts of shenanigans from him and the rest of the team, including Wings of Mercy, Vantage, and charged specials. Bonfire will take advantage of his large defense, and help him should he need to attack something with decent defense.
Lunge is a pretty nasty B skill to have on defense, if a player isn't paying attention it can leave them out of position and lead to their units getting killed, and is also capable of removing units from defense tiles, which might have otherwise allowed it to survive. There are a large number of suitable B substitutes as well, such as Swordbreaker, and even keeping Obstruct on him. Swordbreaker gives him the ability to effectively kill reds and proc bonfire while on his Brave set. Obstruct forces players to deal with Stahl, and protects the much more vulnerable blade mages he is paired with, giving them an opportunity to shred the enemy team.
Draw Back and a Cavalry buff skill are very important for putting him on a cavalry team, preferably one with Blade wielding mages. Draw Back and Rally can be used to make players miscalculate the attack range of Stahl, and any blade mage he Draws Back.
Hone Cavalry is usually in danger of the AI leaving your units out of position, however, so long as Stahl has Rally res, the AI should keep him next to one other unit, and Rally Res will help prevent debuffs from ploy skills, which are all the rage these days. Draw back has a chance of failing since if there is not enough room to use it he will run off and do something else, but otherwise should also be suitable while large open maps are in rotation. Draw Back has the advantage of continuously drawing back your units, effectively keeping them out of enemy range, and making it very hard to predict where they will end up.
The second set, Wo Dao, Moonbow, Vantage, would be to try and catch someone who isn't paying much attention to his skills and puts him into vantage range, where he has an opportunity to OHKO a large number of units. Additionally the without the speed penalty of the brave weapon doubling Stahl will be much harder.
While he is usable enough for other purposes, there are a lot of heroes that can do whatever he does much better. However, being Arena Bait, is not one of those things many units can do better than Stahl.
This ought to help anyone using Horse Emblem on arena defense get a few more defense wins from people not expecting to run into someone serious with Stahl, the Arena Chumpion at the front.
YourBestFriendJ0 & Co.