7: 7 symbol expands all over its reel and substitutes any symbol except X

Bonus X:
This feature is activated by getting 3 “X” symbols on the reels and remains active until the player makes a combination.
If during this phase the player gets 3 more Xs, the multiplier goes to x3 and so on up to a maximum multiplier of x5.
The phase ends with the first winning spin.