Because
Return from the Different Dimension places a connection point on the monsters it brought back. That connection point is checked at the End Phase so the last portion of its effect resolves.
But like I've said, my ruling on
Threatening Roar is just an opinion. I'm probably wrong anyway. I also would mind if you toned it down with the attitude. It isn't very respectful towards me or anyone else that have placed their opinion on the situation nor does it follow the rules of the site. There's already been a couple members that have shown this kind of behavior on the site. Just don't want it to happen to you. This isn't a threat, but rather I'm just looking out for you. =P
If the link
Threatening Roar's text reads is what you say, then a lot of people were wrong. If not then a lot of people were still wrong anyway. Either way, people are going to be wrong.
I think the problem here lies more with reading too much into the card text and comparing it too much with other card text and rulings. After you've read so much into the card text you most likely increase your chances of making a critical error and misunderstand something. I believe that was the case with me; hasn't been the first time.
So with the excellent point you've made about how a player can't attack without a monster and how monsters can't attack on their own changes my entire opinion.
And yes, I do have information to back up my logic behind changing my mind.
Monsters can't attack without a player just as much as a player can't attack without a monster. This fact is so simple that it disproves
Threatening Roar preventing Wildheart from attacking 100%. Let me go into more detail.
The only cards that really affect the player are those cards that force a player to skip a game phase. Such as
Soul Exchange and Battle Phase,
Solomon's Lawbook and Standby Phase,
Fenrir and Draw Phase,
Time Seal and Draw Phase,
Timeater and Main Phase 1, and any other card that forces a player to skip a game phase.
Other cards that affect the player and not monsters are cards like
Cold Wave,
Non Aggression Area,
Scapegoat activated in the same turn and the player can't summon; same goes for
Stray Lambs,
Timidity, and any other card that prevents a player from preforming a certain action. Even the effects of
Jinzo and
Spell Canceller affect the players because of the whole part about Spell/Trap cards can't be activated while their face up on the field.
I'm glad you corrected me on this ruling Masterwoo0. However, I'd like to point out there's a monster in SOI with the same exact effect as
Elemental Hero Wildheart. It will be interesting to see if added rulings like with
Threatening Roar pop up with it or not. If not, then at least we have a bulletproof ruling and explaination to use in giving to a player that disagrees with us at an event. Naturally, if they appeal and the Head Judge rules differently, you'll have to use the ruling that the Head Judge uses and discuss it later with him/her.
=P