Sol Talisman

A card with no mana cost can't be cast normally; you'll need a way to cast it for an alternative cost or without paying its mana cost, such as by suspending it.

If a card with no mana cost is given an alternative cost equal to its mana cost (by Snapcaster Mage, for example), that cost cannot be paid and the card cannot be cast this way.

Suspend is a keyword that represents three abilities. The first is a static ability that allows you to exile the card from your hand with the specified number of time counters (the number before the dash) on it by paying its suspend cost (listed after the dash). The second is a triggered ability that removes a time counter from the suspended card at the beginning of each of your upkeeps. The third is a triggered ability that gives you the option to cast the card when the last time counter is removed.

The mana value of a spell cast without paying its mana cost is determined by its mana cost, even though that cost wasn't paid.

If an effect refers to a "suspended card," that means a card that (1) has suspend, (2) is in exile, and (3) has one or more time counters on it.

Exiling a card with suspend isn't casting that card. This action doesn't use the stack and can't be responded to.