Yes. The characters put onto the battlefield will all attack that turn (one at a time), but you can attack with a character as normal. That could be Trypticon or a different character that was already on the battlefield.
What happens if one of the characters I put onto the battlefield is somehow KO’d before the turn ends? Is it still put under Trypticon?
[Source: WotC]
No. If the character gets KO’d, it will just stay in the KO area at end of turn.
Can I play this card if only one or two of the characters are in the KO area?
[Source: WotC]
Yes. You’ll put as many of the three characters onto the battlefield as you can. For example, let’s say you have Full-Tilt on the battlefield, Wipe-Out in the KO area, and Brunt under Trypticon. Playing Relentless Invasion will put Wipe-Out onto the battlefield. It will attack this turn and then be put back under Trypticon. Full-Tilt doesn’t have to attack, and at the end of the turn it will stay on the battlefield.
For Relentless Invasion, do you have to have all three minions KO’d or can you revive one or two of them?
[Source: WotC]
They don’t all have to be in the KO area. Whichever ones are there can be put onto the battlefield. Only the characters deployed this way go back under Trypticon at the end of your turn.
If you have
Trypticon untapped initially, and your opponents’ characters are also all untapped, and I play Relentless Invasion to bring back Wipe Out, Full Tilt and Brunt, since the effect of Invasion allows you to attack with them all, can Trypticon attack as well?
[Source: WotC]
Yes. The attack granted to his three minions is in addition to your normal attack that turn.
I have
Trypticon and Full-Tilt on the battlefield untapped, with Wipeout and Brunt in the KO area. I play Relentless Invasion, returning the two KOed bots to the battlefield and attack with them. Am I then required to attack with Trypticon or Full-Tilt?
[Source: WotC]
If your opponent is entirely tapped out, you must attack with both characters. If not, you can attack with one or the other (not both), but you don’t have to.
Relentless Invasion returns Wipeout to the battlefield, I flip him to Bot mode, and attack with him. After he gets pulled back under
Trypticon, I use
Battlefield Incursion the next turn to replay him. Does Wipeout enter the battlefield in Bot mode or Alt mode?
[Source: WotC]
Alt mode.
By default all characters start in the mode showing their star cost. So the minions, while not visible under Trypticon and
Metroplex are in alt mode. Note that while Relentless Invasion card does provide a way for a Trypticon minion to be under Trypticon in bot mode, it will be deployed in Alt mode (per WotC FAQ).