Whenever Carth enters or a planeswalker you control dies, look at the top seven cards of your library. You may reveal a planeswalker card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
Planeswalkers' loyalty abilities you activate cost an additional +1 to activate.
(18/06/2021)
The total cost of a planeswalker's loyalty ability is calculated before any counters are added or removed. If a loyalty ability normally costs -3 to activate, you do not remove three counters from it and then put one counter on it. You remove two counters at one time when you pay the cost.
(18/06/2021)
If you somehow manage to control two Carths (perhaps because of Spark Double), the cost-changing effect is cumulative. In total, loyalty abilities will cost an additional +2 to activate.
(18/06/2021)
If a planeswalker's loyalty ability normally has a cost of +1, Carth's ability makes it cost +2 instead. A cost of 0 would become +1, and a cost of -6 would become -5.
(18/06/2021)
If an effect replaces the number of counters that would be placed on a planeswalker, such as that of Vorinclex, Monstrous Raider, that replacement happens only once, at the time payment is made.