You can exile a card in your hand using suspend any time you could cast that card
Devoted Druid A delightful little combo piece, this Elf Druid debuted in 2008s Shadowmoor set, and it has been granted a number of infinite combos due to its easily abused activated abilities of tapping to add one green mana to your mana pool and the more important one putting a -1/-1 counter on it to untap it
If you import a deck containing cards you don't own, there's a Craft All button by the Done button in deck edit you can use to craft all the missing cards
playing them, copying them, and sacrificing them
If you havent read that article, do yourself a favor and check it out here: (LINK)
I've been looking at the old Astarion and Karlach cards, trying to work out if there's a 'Baldur's Gate effect' that inflates the value above what's normally added by the SL label