Ixhel, Scion of Atraxa

Ixhel doesn't change when you can cast an exiled card. For example, if you exile a creature card without flash, you can cast it only during your main phase when the stack is empty.

Multiple instances of toxic are cumulative. For example, if a creature has toxic 2 and gains toxic 1 due to another effect, combat damage that creature deals to a player will cause that player to get 3 poison counters.

Any other effects of that damage, such as life gain from lifelink, still apply.

Conversely, replacement effects that apply to the number of counters put on a player can modify the counters placed this way. For example, Vorinclex, Monstrous Raider's last two abilities can apply to counters placed this way.

Casting an exiled card causes it to leave exile. You can't cast it multiple times.

You pay the costs for an exiled card if you cast it. You may pay any alternative costs the card has rather than the card's mana cost.