Ah Reweave, the situationally-better Polymorph. This is card also serves as a lesson as to why making new card types can be dangerous if you don't pay attention to older stuff (before errata, a Reweaved Diviner's Wand could become a Consuming Bonfire because there were both Tribal cards). Anyway, let's get back on track. This card is great because it's one of blue's only hard permanent destruction cards (Reality Acid is blue's only other destroy permanent option without going into colourless) and it cause the permanent to be sacrificed so it gets around indestructible too (so you're Ulamog, the Infinite Gyre is now a... Chimney Imp). This is also at Instant speed meaning you can pull off some great combat tricks (like turning your opponent's Akroma's Memorial into a Wayfarer's Bauble). However, the major problem with this card is that it costs 6. Sure, it only costs 4 when you splice it onto an Arcane spell (Splice is an underrated mechanic in my opinion since it's essentially Buyback) but you're paying at least 1 for the Arcane spell so you're actually paying 5. However, Polymorph only costs 1 less for Sorcery-speed creature destruction, so I guess that's not too expensive...
Pros: Hits any permanent, forces controller to sack it, Instant speed
Cons: Controller gets a replacement, costs 6 (or 5)