Bruhh
An item that boosts your monsters the fewer tier 1+ synergies you have would be a great addition. Adding +5 speed may be a bit too overpowered, as (for example) if you had that item when you had seven synergies that weren't tier 1+, each of your monsters would gain +35 speed which is ridiculously overpowered in addition to the +70 atk, def, and hp. Probably a +3 or +2 speed instead would be better, and also gaining int too. Overall, this is a great concept, and has the chance to be really overpowered, especially with the reforging and merging possibilities with the forge. Nerfing this even more should probably happen, as this has the possibility of becoming really powerful really quickly, especially if someone manages to find two in a single run. I like the unique idea of an item that instead of buffing synergies by adding one to a monster, it buffs monsters based on synergies a player doesn't have.