Reggie really changes in strength based on the availability of tokens and cheap removal, but it's almost always better Baneslayer than Baneslayer. Even if you're just chumping, he demands a sacrifice every turn or takes a third of your life, as opposed to most similar threats which will take a quarter or a fifth, so that's a lot harder to handle. Plus, he comes down T3, not T4 or T5, so even though he's a lot easier to deal with he forces a lot of subpar plays to just not die to the T-Rex. Also, if you can use the discard in any way at all (which can be super easy if your cube is set up to have those things [like a graveyard combo cube, for example??]) he becomes just crazy good.
In your (current) cube, Inscho, you only have sixteen creatures which can deal with this via deathtouch or having 6+ power, meaning that if you want to deal with it through combat you're gonna need to double block. Red is going to have a tough time dealing with this in general.
I think that you in particular only have a handful of kill spells that deal with Reggie cleanly, and none cost less than MV3 other than
Unexpected Journey. I would expect him to be very strong. Maybe not too strong, as he's clearly tied into themes, and it seems like decks are going to have the levels of synergy required to overcome this power, but I'm sure he'll at least be format-defining.