To get a lvl 20 to Magisters' Terrace you will need a help from warlock who will summon you inside the dungeon. During the summoning process you have to be (for example) in skirmish arena so your level is higher and thus summon is possible.
The minimum level required to enter Magisters' Terrace...
Haven't played my 20 twink in a while so I am wondering if Ooze trinket still works. I am assuming I need present time line but then I can't use portal to Shadowlands (could ask any mage..yea) but when entering normal version of Theater of Pain in present time it says I need to be lvl 50 or...