Every run-through he has, he's exploiting Larian's poor design decisions, and deviations from actual 5E rules. Those systems don't exist to be exploited if Larian doesn't include them.
As to your "Level 4 Insta"kill" Tiamat Cheese", it's dead off the bat if you actually read the post "This is just a thought experiment and not a viable in a real game in any way whatsoever... However..." and then goes on to rely on Wait until you have a Natural 20 on Portent and another that is either Low or High. and Hopefully beat Tiamat on initiative (using the second Portent to help)
That's a far cry from Sin Tee putting multiple videos up of him using Larian's poor design decisions to solo run the game. At this point you just sound like an apologist TBH.
The fact that he's using every broken Larian homebrew rule to do this with a single character, has no bearing on the fact that their homebrew rules, are in fact, broken.
Actually, the non-viable part of the level 4 Tiamat Cheese is getting access to Wave, a legendary weapon. The 2x portent rolls aren't impossible - and the initiative part is mainly to ensure the thought experiment has a 100% success rate (which even Sin Tee doesn't get in his attack rolls). Realistically, investing in the lucky or alert feat will basically guarantee a success it since Tiamat has a whooping +0 to initiative. Or better yet in a videogame context - reload.
The point is that RAW 5e is ripe with potential abuses, and without a DM to manage metagaming and videogame-isms like reloads, the system can be broken.
If you're simply going to be calling people with differing opinions apologists, I honestly don't see a point in further discussion.
Getting wave isn't the only ridiculous and "never happening" part of that scenario. Read up on Tiamat's abilities, there's a reason she's level 30 CR.
Frightful Presence. Each creature of Tiamat's choice that is within 240 feet of Tiamat and aware of her must succeed on a DC 26 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to Tiamat's Frightful Presence for the next 24 hours.
Frightened creatures can't willingly move closer to the source of their fright; a level 4 character never gets close enough to make use of portent, haste, or wave.
Regardless, none of that exercise in creating a ridiculous scenario that has no chance of actually occurring in tabletop DnD, has any bearing on Sin Tee's actually video proof of Larian's homebrew rules being broken in their deviation from actul 5th edition.
