I’d say don’t look at your current situation but what is best long term.
Panther was one of my first legendaries and i thought she was bad as i had no idea of color stacking. Truth is, elemental defense down heroes are very important - not only on titans, but also on offense. And that’s what matters most on the long run. So I would still not miss the chance on the teltoc heroes.
If you are really not interested in them whatsoever, I think valhalla and costume chamber are the best portals at the moment. You also get ascension chests which is an important factor. In the end you don’t wanna just get the heroes, you also wanna max them. Also, next round of costume chamber will include elemental defense down heroes as well - only 5* though i think.
Talking about ascension mats: besides quests, high level titans are the best resource for them. Even if you beat small titans currently, you should aim to beat higher ones in future and have the right heroes ready by then. Unless you wanna wait for AMs forever.
Of course, if all that isn’t important to you, do whatever fits your needs
And if you really don’t like teltoc, i would save event coins for wonderland.
Btw, anchor has a video on YouTube about which portals are the best. Maybe that could help you in making your decision…