I have all the archers available. Then a ton of other units that I got items to reduce the total needed for the bonus. Early on I just was really strong and now it looks like the scaling broke after continuing in endless mode. Unless it is patched I will likely never lose this run.
I meant that I don't have an archer synergy available in my options. I have three stars on all the maps, so there shouldn't be anything left for me to unlock. (What bonus does the archer synergy give you? Bigger range?)
The archer synergy was in the game but its not anymore - there's not enough unlock slots right now for all the unlocks supposed to be in the game and this is an OG player that had unlocked it while it was still in.
Archer synergy gives a chance to fire multiple projectiles.