How to be frends with mecenary

[Nerx]

idk. maybe somone is going to help i googled it and nothing and if you know also post what time is "days" are, do it like this -"days are xx minutes and mecenary after xxx uses"

[Gem of Temporarity]

days are 10 training stat-ups or a fight(one endless stage is 1 fight) minutes and mercenary after 2(uses per contract)x4(amount of pre-friend friendship levels if memory serves)x2 or 3(I don't remember the amount of contracts between friendship level exactly) uses.