Hey so question about Tera effectiveness: when you terastillize, will this increase the effects of moves that don’t deal damage? For example, status moves, stat increase moves, things like “helping hand” etc.
As I understand it, Terastalization only affects your moves' damage and the Pokemon's own type, so anything that doesn't deal damage won't be affected, nor will the chances of any side effects of moves regardless of whether or not they match your Tera type. The exception is that moves that alter your pokemon's type will have that effect overridden, and while that doesn't come into play too often, there is a niche strategy of having T-Electric Pawmot use Double Shock and keep its STAB intact. I'd imagine the same could be said of Burn Up if any pokemon could still use it.
Also, between the original time of this reply and the edit I'm making now, I managed to get an Ability Patch, so I was able to do some testing with my Sylveon regarding how Tera Blast interacts with Pixilate. Whn not Terastalized, it turns into a Fairy type move just like any other Normal move (although this isn't represented by the type symbols when selecting moves). However, if Sylveon is T-Normal, Terastalizes, THEN uses Tera Blast, the attack remains Normal type. Hyper Voice, on the other hand, did turn into a Fairy move, but still seems to get the extra sparkly animation just like other Normal attacks do. I can't really test if Hyper Voice is getting the Pixilate boost, but I can try changing it to T-Fairy once I get enough shards to do so to see if Hyper Voice still gets Tera-boosted when Sylveon is Terastalized to Fairy type. If it doesn't, then T-Fairy Sylveon may well be better off with Moonblast and Cute Charm if you intend it to be the main Tera pokemon on your team.
If there's anyone here who can run some actual damage tests, that'd be dope. I'd love to know how Tera Blast and Hyper Voice's damage is actually being affected; depending on how the Tera boost applies and whether Pixilate's damage boost applies or not, they could be getting a 1.5x, 1.8x, 2x, or 2.4x multiplier overall. And this is all assuming there's no special math applying like for Terastalized pokemon with Adaptability. (My guess is that Hyper Voice is getting 1.8x and Tera Blast is getting 2x but again, no way to be 100% sure.)