So here in this sentence below "との" was used 2 times. What does との standfor? Can someone please explain it to me?
これまで数多くのアニメ作品とのコラボを実現してきた痛印堂には、「好きなアニメとのコラボは嬉しいけど、自分の好きなキャラクターがいない！」「メインキャラクターだけでなく違う子もお願いします！」などの声が届いており、その要望に応えるべく今回の「ガールズ＆パンツァー」痛印第2弾が実現しました。
Generally speaking:
〜と links to a following verb (or other predicate)
〜との links to a following noun (or noun equivalent)
That's generally what の does—indicates a relationship to a following noun:
海へ 行く The particle へ links 海 to the following verb 行く
海への道 The particle の links 海へ to the following noun 道
In English, we use word order instead of a particle:
go [ to the sea ]
the road [ to the sea ]
We can tell that the to-phrase relates to the verb go or to the noun road because they're next to each other. But that doesn't work in Japanese—you need to specify that it relates to a noun by adding の.
Likewise, in your example, 好きなアニメと needs の to relate to the following noun, コラボ. In English we could just say "collaboration [ with 〜 ]", but in Japanese you need to add の.
