Shradow

Sounds very similar to Blazon Summons in the DL raid events. You get Blazons from the boss/raid battle to pull items from a box that you can reset once you empty it (or for the first 4 boxes, once you pull the copy of the free Dragon for the event), but the box itself only has things like crafting materials and gold and a handful of equipment items and stuff, no premium currency.

Though there is a special EX version of the raid boss that you can sometimes fight after doing Expert/Nightmare mode which goes away once you beat it until the next time you unlock it, and the reward pool for that has summoning tickets in it, albeit at a pretty rare drop rate. So with infinite grinding you could technically get a ton of summoning tickets, though it's not like it's consistent or anything.

Btw that "first four boxes can be reset on drawing the best item in them" thing is exactly how it works in gbf too, down to the number of boxes. Same for the extra special boss that only sometimes spawns after battles. It doesn't drop tickets but it hasa very small chance to drop 1/30th of a damascus ingot

Same for the EX boss in DL, it can drop Damascus Shards which 10 can be traded for an Ingot, and other similar 1/10th items. I assume GBF has a similar Unbind mechanic for weapons and stuff.