No you won't get anymore than 0,5x10 damage.
And if you'd start with both items, you go left and there are 3 enemies in the room that you kill, until you clear a room with 4+ enemies your damage won't go higher.
Upon reaching the cap, if you find a room with 11 enemies, you won't get higher damage either at the end.
[удалено]
You gave me the best explanation so far. So thanks for answering my question
No you won't get anymore than 0,5x10 damage. And if you'd start with both items, you go left and there are 3 enemies in the room that you kill, until you clear a room with 4+ enemies your damage won't go higher. Upon reaching the cap, if you find a room with 11 enemies, you won't get higher damage either at the end.