Co-Op Easter Egg Question

[SacredContagion]

A friend and I are attempting to complete the easter egg, just the two for us. 

My question is, do we need to get all 4 UPGRADED bows, or do we only need to upgrade 2 of them in order to complete the easter egg?

[Nieno69]

You need only two ... in the keeper step you both need to do it 2 times each bow... I suggest storm and fire 

But storm and Wolf are the fastest to do i think... 

 

[DaveLo07]

Make sure that you set the game to ranked, as non-ranked games will require all 4 bows, regardless of how many players are in the game.