The passive, named "Reflecting Shield," says it will:
2. 50% of the damage taken by allies
So, when I'm attacked by someone like shade (hero chosen randomly, any name would do) for... let's say 1000 damage, you'd expect that one of two amounts is returned, depending on your definition of "REFLECT" - he'll take either 500 (50% of the damage dealt to your hero), or 1000 (because 50% of the attack's damage was reflected back to him, meaning you didn't have to suffer it). What's happening right now is you're taking that 1000, and he's taking a hearty 100-250. The 50% part of the ability is not showing up, simply put.
Now, let's talk about the term "reflect." When you hear "reflects damage" you imagine something preventing the damage by bouncing it back towards the source, effectively turning defense into offense. This is not what Alexandros does. What he's doing is granting a "thorns" aura to his allies, returning a percentile of damage suffered back unto the attacker. I'm okay with this, it just means Alexandros is a lot weaker than advertised (especially since he didn't get an epic to go with his rework).
Now, there's one more problem with the ability: when Alexandros takes a fatal hit (something like a big 14-32k Plummeting Doom from Agnon, most commonly), he reflects 0 damage. The hit that kills him returns nothing, putting him in an even worse position when it comes time to make the call on who's going raiding. This one is a huge problem, and needs immediate fixing.
This last tidbit might be a bug, but I've had it happen a few times where an opponent will use an ability and take 0 damage back from the reflect, because if they take anything back it'd kill them (i.e. the reflect set them to 1). I don't know if his reflect is supposed to be nonlethal, but if it is, it'd be good to have that clarified ASAP.
EDIT: After extensive testing the past few days (read: playing with him because event quests keep telling me to), I've had a significant number of situations come up where the damage return does not kill an opponent; it's definitely nonlethal damage.
The whole situation covered above isn't great, guys. If constructs are going to get some love, it'd be good to start ironing out the kinks as early as possible.
Alexandros gives thorns - doesn't reflect the right % - doesn't damage on death - reflect damage is nonlethal
Hopper will eat literally anything; rocks (stonefist), scrap metal (the furnace), ash (solaris), even bone (a lot of examples lol), AND is a known carrier of disease, and yet she still finds herself suffering from the disease ailment most matches... Something must be done!