Can Fragmentize destroy artifacts with converted mana cost greater than 4?
No, Fragmentize cannot destroy artifacts with mana value/converted mana cost 5 or higher
There are several cards with rules text worded similarly to Fragmentize. One such card, Eliminate from Core Set 2021, reads &quot;Destroy target creature or planeswalker with converted mana cost 3 or less.&quot;
One of the Oracle rulings for Eliminate specifies &quot;If a creature or planeswalker on the battlefield has X in its mana cost, X is considered to be 0.&quot;
If the intention for Eliminate was that its text be read as &quot;Destroy [target creature] or [target planeswalker with converted mana cost 3 or less]&quot;, then the word &quot;creature&quot; would not need to be in that ruling, since that version of Eliminate wouldn't care about a creature's CMC. (The digital implementation of Eliminate on MTG Arena also doesn't allow targeting a creature with CMC &gt; 3. Also, it's worth noting that a spell that unconditionally destroyed any creature for 1B, and ALSO could destroy some planeswalkers, would be more powerful than for example Doom Blade, which is a very good card in its own right.)
From this we can conclude that Eliminate is intended to be read as &quot;Destroy target [creature or planeswalker] with converted mana cost 3 or less.&quot; Further, since the wording of Fragmentize is nearly identical to the wording of Eliminate except for the slightly different CMC and types of permanents it targets, it can be demonstrated that the intended reading of Fragmentize is &quot;Destroy target [artifact or enchantment] with converted mana cost 4 or less.&quot;