People say super awakening and UR gear is an issue, but costumes upgrades are worse by FAR. Takes 30 material which if you don't have valentines unit is like 30 hell raids for a single upgrade! You need 30 materials for each max upgrade and you need that 15 times to fully max a character.
That sums up to 450 materials meaning about 400 raids for a SINGLE CHARACTER! Now multiple that for your 4 units in your squad and thats about 1600 raids, and 3200 if including links! Takes 90 million gold to upgrade it and 180 including associations.
Without valentines units thats about 265 days assuming you get an even of red, grey, and howlex demon which is very unlikely. By 265 days your team isn't even meta anymore! It's such a ridiculous system and simply not fair for all free to play players