It is impossible to have a fully maxed Maeve’s Buffalord at this time without taking advantage of an exploit.
Update 1.6 July 25th, 2019 - Maeve’s Buffalord added to Alpha chest
Update 1.7 Sept. 24th 2019 - fully maxed Maeve’s Buffalord seen in Arena
60 days have gone by from the introduction of Maeve’s Buffalord until a fully maxed dragon was spotted
A maxed 5-star Maeve’s Buffalord requires 3000 trust points
A level 10 Alpha chest contains 50 trust points
Therefore, 60 Level 10 Alpha chests would need to be opened
This means a Level 10 Alpha chest was opened every day since the dragon was released
A Lvl 10 Alpha Chest requires 400 keys to open
60 chest * 400 keys/chest = 24,000 keys needed
60 days * 24 hours / day * 1 energy / 4 hours * 10 keys / 1 energy = 3,600 keys
135 bonus keys / day * 60 days = 8,100 keys (assuming #1 spot defeating level 10 Alpha every day for 60 days)
The absolute possible best case scenario is a total of 11,700 keys
This means 24,000 - 11,700 = 12,300 keys is unaccounted
Purchasing Alpha bonus energy would not be enough to satisfy the amount
The only way these players were able to obtain enough keys is by clan hopping in private clans to defeat multiple Alphas on a daily basis.